diff --git a/amazonka-apigateway/gen/Network/AWS/APIGateway/Types/Sum.hs b/amazonka-apigateway/gen/Network/AWS/APIGateway/Types/Sum.hs
index e276d36f3bd..daed66c7e28 100644
--- a/amazonka-apigateway/gen/Network/AWS/APIGateway/Types/Sum.hs
+++ b/amazonka-apigateway/gen/Network/AWS/APIGateway/Types/Sum.hs
@@ -30,7 +30,7 @@ instance FromText AuthorizerType where
         "cognito_user_pools" -> pure CognitoUserPools
         "token" -> pure Token
         e -> fromTextError $ "Failure parsing AuthorizerType from value: '" <> e
-           <> "'. Accepted values: COGNITO_USER_POOLS, TOKEN"
+           <> "'. Accepted values: cognito_user_pools, token"
 
 instance ToText AuthorizerType where
     toText = \case
@@ -114,7 +114,7 @@ instance FromText CacheClusterStatus where
         "flush_in_progress" -> pure FlushInProgress
         "not_available" -> pure NotAvailable
         e -> fromTextError $ "Failure parsing CacheClusterStatus from value: '" <> e
-           <> "'. Accepted values: AVAILABLE, CREATE_IN_PROGRESS, DELETE_IN_PROGRESS, FLUSH_IN_PROGRESS, NOT_AVAILABLE"
+           <> "'. Accepted values: available, create_in_progress, delete_in_progress, flush_in_progress, not_available"
 
 instance ToText CacheClusterStatus where
     toText = \case
@@ -146,7 +146,7 @@ instance FromText IntegrationType where
         "http" -> pure HTTP
         "mock" -> pure Mock
         e -> fromTextError $ "Failure parsing IntegrationType from value: '" <> e
-           <> "'. Accepted values: AWS, HTTP, MOCK"
+           <> "'. Accepted values: aws, http, mock"
 
 instance ToText IntegrationType where
     toText = \case
@@ -242,7 +242,7 @@ instance FromText UnauthorizedCacheControlHeaderStrategy where
         "succeed_with_response_header" -> pure SucceedWithResponseHeader
         "succeed_without_response_header" -> pure SucceedWithoutResponseHeader
         e -> fromTextError $ "Failure parsing UnauthorizedCacheControlHeaderStrategy from value: '" <> e
-           <> "'. Accepted values: FAIL_WITH_403, SUCCEED_WITH_RESPONSE_HEADER, SUCCEED_WITHOUT_RESPONSE_HEADER"
+           <> "'. Accepted values: fail_with_403, succeed_with_response_header, succeed_without_response_header"
 
 instance ToText UnauthorizedCacheControlHeaderStrategy where
     toText = \case
diff --git a/amazonka-application-autoscaling/gen/Network/AWS/ApplicationAutoScaling/Types/Sum.hs b/amazonka-application-autoscaling/gen/Network/AWS/ApplicationAutoScaling/Types/Sum.hs
index 4edd4fbf392..4eb4f56f354 100644
--- a/amazonka-application-autoscaling/gen/Network/AWS/ApplicationAutoScaling/Types/Sum.hs
+++ b/amazonka-application-autoscaling/gen/Network/AWS/ApplicationAutoScaling/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText AdjustmentType where
         "exactcapacity" -> pure ExactCapacity
         "percentchangeincapacity" -> pure PercentChangeInCapacity
         e -> fromTextError $ "Failure parsing AdjustmentType from value: '" <> e
-           <> "'. Accepted values: ChangeInCapacity, ExactCapacity, PercentChangeInCapacity"
+           <> "'. Accepted values: changeincapacity, exactcapacity, percentchangeincapacity"
 
 instance ToText AdjustmentType where
     toText = \case
@@ -63,7 +63,7 @@ instance FromText MetricAggregationType where
         "maximum" -> pure Maximum
         "minimum" -> pure Minimum
         e -> fromTextError $ "Failure parsing MetricAggregationType from value: '" <> e
-           <> "'. Accepted values: Average, Maximum, Minimum"
+           <> "'. Accepted values: average, maximum, minimum"
 
 instance ToText MetricAggregationType where
     toText = \case
@@ -91,7 +91,7 @@ instance FromText PolicyType where
     parser = takeLowerText >>= \case
         "stepscaling" -> pure StepScaling
         e -> fromTextError $ "Failure parsing PolicyType from value: '" <> e
-           <> "'. Accepted values: StepScaling"
+           <> "'. Accepted values: stepscaling"
 
 instance ToText PolicyType where
     toText = \case
@@ -117,7 +117,7 @@ instance FromText ScalableDimension where
     parser = takeLowerText >>= \case
         "ecs:service:desiredcount" -> pure EcsServiceDesiredCount
         e -> fromTextError $ "Failure parsing ScalableDimension from value: '" <> e
-           <> "'. Accepted values: ecs:service:DesiredCount"
+           <> "'. Accepted values: ecs:service:desiredcount"
 
 instance ToText ScalableDimension where
     toText = \case
@@ -153,7 +153,7 @@ instance FromText ScalingActivityStatusCode where
         "successful" -> pure Successful
         "unfulfilled" -> pure Unfulfilled
         e -> fromTextError $ "Failure parsing ScalingActivityStatusCode from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Overridden, Pending, Successful, Unfulfilled"
+           <> "'. Accepted values: failed, inprogress, overridden, pending, successful, unfulfilled"
 
 instance ToText ScalingActivityStatusCode where
     toText = \case
diff --git a/amazonka-autoscaling/gen/Network/AWS/AutoScaling/Types/Sum.hs b/amazonka-autoscaling/gen/Network/AWS/AutoScaling/Types/Sum.hs
index 6ad67971b45..1f73b4f6d59 100644
--- a/amazonka-autoscaling/gen/Network/AWS/AutoScaling/Types/Sum.hs
+++ b/amazonka-autoscaling/gen/Network/AWS/AutoScaling/Types/Sum.hs
@@ -51,7 +51,7 @@ instance FromText LifecycleState where
         "terminating:proceed" -> pure TerminatingProceed
         "terminating:wait" -> pure TerminatingWait
         e -> fromTextError $ "Failure parsing LifecycleState from value: '" <> e
-           <> "'. Accepted values: Detached, Detaching, EnteringStandby, InService, Pending, Pending:Proceed, Pending:Wait, Quarantined, Standby, Terminated, Terminating, Terminating:Proceed, Terminating:Wait"
+           <> "'. Accepted values: detached, detaching, enteringstandby, inservice, pending, pending:proceed, pending:wait, quarantined, standby, terminated, terminating, terminating:proceed, terminating:wait"
 
 instance ToText LifecycleState where
     toText = \case
@@ -108,7 +108,7 @@ instance FromText ScalingActivityStatusCode where
         "waitingforspotinstanceid" -> pure WaitingForSpotInstanceId
         "waitingforspotinstancerequestid" -> pure WaitingForSpotInstanceRequestId
         e -> fromTextError $ "Failure parsing ScalingActivityStatusCode from value: '" <> e
-           <> "'. Accepted values: Cancelled, Failed, InProgress, MidLifecycleAction, PendingSpotBidPlacement, PreInService, Successful, WaitingForELBConnectionDraining, WaitingForInstanceId, WaitingForInstanceWarmup, WaitingForSpotInstanceId, WaitingForSpotInstanceRequestId"
+           <> "'. Accepted values: cancelled, failed, inprogress, midlifecycleaction, pendingspotbidplacement, preinservice, successful, waitingforelbconnectiondraining, waitingforinstanceid, waitingforinstancewarmup, waitingforspotinstanceid, waitingforspotinstancerequestid"
 
 instance ToText ScalingActivityStatusCode where
     toText = \case
diff --git a/amazonka-certificatemanager/gen/Network/AWS/CertificateManager/Types/Sum.hs b/amazonka-certificatemanager/gen/Network/AWS/CertificateManager/Types/Sum.hs
index f73f01ea76d..f20caa02233 100644
--- a/amazonka-certificatemanager/gen/Network/AWS/CertificateManager/Types/Sum.hs
+++ b/amazonka-certificatemanager/gen/Network/AWS/CertificateManager/Types/Sum.hs
@@ -39,7 +39,7 @@ instance FromText CertificateStatus where
         "revoked" -> pure Revoked
         "validation_timed_out" -> pure ValidationTimedOut
         e -> fromTextError $ "Failure parsing CertificateStatus from value: '" <> e
-           <> "'. Accepted values: EXPIRED, FAILED, INACTIVE, ISSUED, PENDING_VALIDATION, REVOKED, VALIDATION_TIMED_OUT"
+           <> "'. Accepted values: expired, failed, inactive, issued, pending_validation, revoked, validation_timed_out"
 
 instance ToText CertificateStatus where
     toText = \case
@@ -79,7 +79,7 @@ instance FromText FailureReason where
         "no_available_contacts" -> pure NoAvailableContacts
         "other" -> pure Other
         e -> fromTextError $ "Failure parsing FailureReason from value: '" <> e
-           <> "'. Accepted values: ADDITIONAL_VERIFICATION_REQUIRED, DOMAIN_NOT_ALLOWED, INVALID_PUBLIC_DOMAIN, NO_AVAILABLE_CONTACTS, OTHER"
+           <> "'. Accepted values: additional_verification_required, domain_not_allowed, invalid_public_domain, no_available_contacts, other"
 
 instance ToText FailureReason where
     toText = \case
@@ -108,7 +108,7 @@ instance FromText KeyAlgorithm where
         "ec_prime256v1" -> pure EcPRIME256V1
         "rsa_2048" -> pure Rsa2048
         e -> fromTextError $ "Failure parsing KeyAlgorithm from value: '" <> e
-           <> "'. Accepted values: EC_prime256v1, RSA_2048"
+           <> "'. Accepted values: ec_prime256v1, rsa_2048"
 
 instance ToText KeyAlgorithm where
     toText = \case
@@ -150,7 +150,7 @@ instance FromText RevocationReason where
         "superceded" -> pure Superceded
         "unspecified" -> pure Unspecified
         e -> fromTextError $ "Failure parsing RevocationReason from value: '" <> e
-           <> "'. Accepted values: A_A_COMPROMISE, AFFILIATION_CHANGED, CA_COMPROMISE, CERTIFICATE_HOLD, CESSATION_OF_OPERATION, KEY_COMPROMISE, PRIVILEGE_WITHDRAWN, REMOVE_FROM_CRL, SUPERCEDED, UNSPECIFIED"
+           <> "'. Accepted values: a_a_compromise, affiliation_changed, ca_compromise, certificate_hold, cessation_of_operation, key_compromise, privilege_withdrawn, remove_from_crl, superceded, unspecified"
 
 instance ToText RevocationReason where
     toText = \case
diff --git a/amazonka-cloudformation/gen/Network/AWS/CloudFormation/Types/Sum.hs b/amazonka-cloudformation/gen/Network/AWS/CloudFormation/Types/Sum.hs
index f25aeab327d..634df675bb1 100644
--- a/amazonka-cloudformation/gen/Network/AWS/CloudFormation/Types/Sum.hs
+++ b/amazonka-cloudformation/gen/Network/AWS/CloudFormation/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText Capability where
         "capability_iam" -> pure CapabilityIAM
         "capability_named_iam" -> pure CapabilityNamedIAM
         e -> fromTextError $ "Failure parsing Capability from value: '" <> e
-           <> "'. Accepted values: CAPABILITY_IAM, CAPABILITY_NAMED_IAM"
+           <> "'. Accepted values: capability_iam, capability_named_iam"
 
 instance ToText Capability where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText ChangeAction where
         "modify" -> pure Modify
         "remove" -> pure Remove
         e -> fromTextError $ "Failure parsing ChangeAction from value: '" <> e
-           <> "'. Accepted values: Add, Modify, Remove"
+           <> "'. Accepted values: add, modify, remove"
 
 instance ToText ChangeAction where
     toText = \case
@@ -90,7 +90,7 @@ instance FromText ChangeSetStatus where
         "delete_complete" -> pure CSSDeleteComplete
         "failed" -> pure CSSFailed
         e -> fromTextError $ "Failure parsing ChangeSetStatus from value: '" <> e
-           <> "'. Accepted values: CREATE_COMPLETE, CREATE_IN_PROGRESS, CREATE_PENDING, DELETE_COMPLETE, FAILED"
+           <> "'. Accepted values: create_complete, create_in_progress, create_pending, delete_complete, failed"
 
 instance ToText ChangeSetStatus where
     toText = \case
@@ -125,7 +125,7 @@ instance FromText ChangeSource where
         "resourceattribute" -> pure ResourceAttribute
         "resourcereference" -> pure ResourceReference
         e -> fromTextError $ "Failure parsing ChangeSource from value: '" <> e
-           <> "'. Accepted values: Automatic, DirectModification, ParameterReference, ResourceAttribute, ResourceReference"
+           <> "'. Accepted values: automatic, directmodification, parameterreference, resourceattribute, resourcereference"
 
 instance ToText ChangeSource where
     toText = \case
@@ -152,7 +152,7 @@ instance FromText ChangeType where
     parser = takeLowerText >>= \case
         "resource" -> pure Resource
         e -> fromTextError $ "Failure parsing ChangeType from value: '" <> e
-           <> "'. Accepted values: Resource"
+           <> "'. Accepted values: resource"
 
 instance ToText ChangeType where
     toText = \case
@@ -177,7 +177,7 @@ instance FromText EvaluationType where
         "dynamic" -> pure Dynamic
         "static" -> pure Static
         e -> fromTextError $ "Failure parsing EvaluationType from value: '" <> e
-           <> "'. Accepted values: Dynamic, Static"
+           <> "'. Accepted values: dynamic, static"
 
 instance ToText EvaluationType where
     toText = \case
@@ -211,7 +211,7 @@ instance FromText ExecutionStatus where
         "obsolete" -> pure Obsolete
         "unavailable" -> pure Unavailable
         e -> fromTextError $ "Failure parsing ExecutionStatus from value: '" <> e
-           <> "'. Accepted values: AVAILABLE, EXECUTE_COMPLETE, EXECUTE_FAILED, EXECUTE_IN_PROGRESS, OBSOLETE, UNAVAILABLE"
+           <> "'. Accepted values: available, execute_complete, execute_failed, execute_in_progress, obsolete, unavailable"
 
 instance ToText ExecutionStatus where
     toText = \case
@@ -243,7 +243,7 @@ instance FromText OnFailure where
         "do_nothing" -> pure DoNothing
         "rollback" -> pure Rollback
         e -> fromTextError $ "Failure parsing OnFailure from value: '" <> e
-           <> "'. Accepted values: DELETE, DO_NOTHING, ROLLBACK"
+           <> "'. Accepted values: delete, do_nothing, rollback"
 
 instance ToText OnFailure where
     toText = \case
@@ -269,7 +269,7 @@ instance FromText Replacement where
         "false" -> pure False'
         "true" -> pure True'
         e -> fromTextError $ "Failure parsing Replacement from value: '" <> e
-           <> "'. Accepted values: Conditional, False, True"
+           <> "'. Accepted values: conditional, false, true"
 
 instance ToText Replacement where
     toText = \case
@@ -298,7 +298,7 @@ instance FromText RequiresRecreation where
         "conditionally" -> pure Conditionally
         "never" -> pure Never
         e -> fromTextError $ "Failure parsing RequiresRecreation from value: '" <> e
-           <> "'. Accepted values: Always, Conditionally, Never"
+           <> "'. Accepted values: always, conditionally, never"
 
 instance ToText RequiresRecreation where
     toText = \case
@@ -333,7 +333,7 @@ instance FromText ResourceAttribute where
         "tags" -> pure Tags
         "updatepolicy" -> pure UpdatePolicy
         e -> fromTextError $ "Failure parsing ResourceAttribute from value: '" <> e
-           <> "'. Accepted values: CreationPolicy, DeletionPolicy, Metadata, Properties, Tags, UpdatePolicy"
+           <> "'. Accepted values: creationpolicy, deletionpolicy, metadata, properties, tags, updatepolicy"
 
 instance ToText ResourceAttribute where
     toText = \case
@@ -363,7 +363,7 @@ instance FromText ResourceSignalStatus where
         "failure" -> pure Failure
         "success" -> pure Success
         e -> fromTextError $ "Failure parsing ResourceSignalStatus from value: '" <> e
-           <> "'. Accepted values: FAILURE, SUCCESS"
+           <> "'. Accepted values: failure, success"
 
 instance ToText ResourceSignalStatus where
     toText = \case
@@ -402,7 +402,7 @@ instance FromText ResourceStatus where
         "update_failed" -> pure UpdateFailed
         "update_in_progress" -> pure UpdateInProgress
         e -> fromTextError $ "Failure parsing ResourceStatus from value: '" <> e
-           <> "'. Accepted values: CREATE_COMPLETE, CREATE_FAILED, CREATE_IN_PROGRESS, DELETE_COMPLETE, DELETE_FAILED, DELETE_IN_PROGRESS, DELETE_SKIPPED, UPDATE_COMPLETE, UPDATE_FAILED, UPDATE_IN_PROGRESS"
+           <> "'. Accepted values: create_complete, create_failed, create_in_progress, delete_complete, delete_failed, delete_in_progress, delete_skipped, update_complete, update_failed, update_in_progress"
 
 instance ToText ResourceStatus where
     toText = \case
@@ -464,7 +464,7 @@ instance FromText StackStatus where
         "update_rollback_failed" -> pure SSUpdateRollbackFailed
         "update_rollback_in_progress" -> pure SSUpdateRollbackInProgress
         e -> fromTextError $ "Failure parsing StackStatus from value: '" <> e
-           <> "'. Accepted values: CREATE_COMPLETE, CREATE_FAILED, CREATE_IN_PROGRESS, DELETE_COMPLETE, DELETE_FAILED, DELETE_IN_PROGRESS, ROLLBACK_COMPLETE, ROLLBACK_FAILED, ROLLBACK_IN_PROGRESS, UPDATE_COMPLETE, UPDATE_COMPLETE_CLEANUP_IN_PROGRESS, UPDATE_IN_PROGRESS, UPDATE_ROLLBACK_COMPLETE, UPDATE_ROLLBACK_COMPLETE_CLEANUP_IN_PROGRESS, UPDATE_ROLLBACK_FAILED, UPDATE_ROLLBACK_IN_PROGRESS"
+           <> "'. Accepted values: create_complete, create_failed, create_in_progress, delete_complete, delete_failed, delete_in_progress, rollback_complete, rollback_failed, rollback_in_progress, update_complete, update_complete_cleanup_in_progress, update_in_progress, update_rollback_complete, update_rollback_complete_cleanup_in_progress, update_rollback_failed, update_rollback_in_progress"
 
 instance ToText StackStatus where
     toText = \case
diff --git a/amazonka-cloudfront/gen/Network/AWS/CloudFront/Types/Sum.hs b/amazonka-cloudfront/gen/Network/AWS/CloudFront/Types/Sum.hs
index 9fcfc04dece..a987092b886 100644
--- a/amazonka-cloudfront/gen/Network/AWS/CloudFront/Types/Sum.hs
+++ b/amazonka-cloudfront/gen/Network/AWS/CloudFront/Types/Sum.hs
@@ -135,7 +135,7 @@ instance FromText Method where
         "post" -> pure Post
         "put" -> pure Put
         e -> fromTextError $ "Failure parsing Method from value: '" <> e
-           <> "'. Accepted values: DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT"
+           <> "'. Accepted values: delete, get, head, options, patch, post, put"
 
 instance ToText Method where
     toText = \case
@@ -169,7 +169,7 @@ instance FromText MinimumProtocolVersion where
         "sslv3" -> pure MPVSSLV3
         "tlsv1" -> pure MPVTLSV1
         e -> fromTextError $ "Failure parsing MinimumProtocolVersion from value: '" <> e
-           <> "'. Accepted values: SSLv3, TLSv1"
+           <> "'. Accepted values: sslv3, tlsv1"
 
 instance ToText MinimumProtocolVersion where
     toText = \case
@@ -232,7 +232,7 @@ instance FromText PriceClass where
         "priceclass_200" -> pure PriceClass200
         "priceclass_all" -> pure PriceClassAll
         e -> fromTextError $ "Failure parsing PriceClass from value: '" <> e
-           <> "'. Accepted values: PriceClass_100, PriceClass_200, PriceClass_All"
+           <> "'. Accepted values: priceclass_100, priceclass_200, priceclass_all"
 
 instance ToText PriceClass where
     toText = \case
@@ -266,7 +266,7 @@ instance FromText SSLProtocol where
         "tlsv1.1" -> pure TLSV1_1
         "tlsv1.2" -> pure TLSV1_2
         e -> fromTextError $ "Failure parsing SSLProtocol from value: '" <> e
-           <> "'. Accepted values: SSLv3, TLSv1, TLSv1.1, TLSv1.2"
+           <> "'. Accepted values: sslv3, tlsv1, tlsv1.1, tlsv1.2"
 
 instance ToText SSLProtocol where
     toText = \case
diff --git a/amazonka-cloudhsm/gen/Network/AWS/CloudHSM/Types/Sum.hs b/amazonka-cloudhsm/gen/Network/AWS/CloudHSM/Types/Sum.hs
index ed7549dafe3..5311c217760 100644
--- a/amazonka-cloudhsm/gen/Network/AWS/CloudHSM/Types/Sum.hs
+++ b/amazonka-cloudhsm/gen/Network/AWS/CloudHSM/Types/Sum.hs
@@ -57,7 +57,7 @@ instance FromText CloudHSMObjectState where
         "ready" -> pure Ready
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing CloudHSMObjectState from value: '" <> e
-           <> "'. Accepted values: DEGRADED, READY, UPDATING"
+           <> "'. Accepted values: degraded, ready, updating"
 
 instance ToText CloudHSMObjectState where
     toText = \case
@@ -94,7 +94,7 @@ instance FromText HSMStatus where
         "terminating" -> pure HSTerminating
         "updating" -> pure HSUpdating
         e -> fromTextError $ "Failure parsing HSMStatus from value: '" <> e
-           <> "'. Accepted values: DEGRADED, PENDING, RUNNING, SUSPENDED, TERMINATED, TERMINATING, UPDATING"
+           <> "'. Accepted values: degraded, pending, running, suspended, terminated, terminating, updating"
 
 instance ToText HSMStatus where
     toText = \case
@@ -127,7 +127,7 @@ instance FromText SubscriptionType where
     parser = takeLowerText >>= \case
         "production" -> pure Production
         e -> fromTextError $ "Failure parsing SubscriptionType from value: '" <> e
-           <> "'. Accepted values: PRODUCTION"
+           <> "'. Accepted values: production"
 
 instance ToText SubscriptionType where
     toText = \case
diff --git a/amazonka-cloudsearch/gen/Network/AWS/CloudSearch/Types/Sum.hs b/amazonka-cloudsearch/gen/Network/AWS/CloudSearch/Types/Sum.hs
index 00027c7b4f2..d09cffe27ae 100644
--- a/amazonka-cloudsearch/gen/Network/AWS/CloudSearch/Types/Sum.hs
+++ b/amazonka-cloudsearch/gen/Network/AWS/CloudSearch/Types/Sum.hs
@@ -128,7 +128,7 @@ instance FromText AnalysisSchemeLanguage where
         "zh-hans" -> pure ZhHans
         "zh-hant" -> pure ZhHant
         e -> fromTextError $ "Failure parsing AnalysisSchemeLanguage from value: '" <> e
-           <> "'. Accepted values: ar, bg, ca, cs, da, de, el, en, es, eu, fa, fi, fr, ga, gl, he, hi, hu, hy, it, id, ja, ko, lv, mul, nl, no, pt, ro, ru, sv, th, tr, zh-Hans, zh-Hant"
+           <> "'. Accepted values: ar, bg, ca, cs, da, de, el, en, es, eu, fa, fi, fr, ga, gl, he, hi, hu, hy, it, id, ja, ko, lv, mul, nl, no, pt, ro, ru, sv, th, tr, zh-hans, zh-hant"
 
 instance ToText AnalysisSchemeLanguage where
     toText = \case
@@ -251,7 +251,7 @@ instance FromText OptionState where
         "processing" -> pure Processing
         "requiresindexdocuments" -> pure RequiresIndexDocuments
         e -> fromTextError $ "Failure parsing OptionState from value: '" <> e
-           <> "'. Accepted values: Active, FailedToValidate, Processing, RequiresIndexDocuments"
+           <> "'. Accepted values: active, failedtovalidate, processing, requiresindexdocuments"
 
 instance ToText OptionState where
     toText = \case
diff --git a/amazonka-cloudtrail/gen/Network/AWS/CloudTrail/Types/Sum.hs b/amazonka-cloudtrail/gen/Network/AWS/CloudTrail/Types/Sum.hs
index aae432976df..01bb3019dda 100644
--- a/amazonka-cloudtrail/gen/Network/AWS/CloudTrail/Types/Sum.hs
+++ b/amazonka-cloudtrail/gen/Network/AWS/CloudTrail/Types/Sum.hs
@@ -35,7 +35,7 @@ instance FromText LookupAttributeKey where
         "resourcetype" -> pure ResourceType
         "username" -> pure Username
         e -> fromTextError $ "Failure parsing LookupAttributeKey from value: '" <> e
-           <> "'. Accepted values: EventId, EventName, ResourceName, ResourceType, Username"
+           <> "'. Accepted values: eventid, eventname, resourcename, resourcetype, username"
 
 instance ToText LookupAttributeKey where
     toText = \case
diff --git a/amazonka-cloudwatch-events/gen/Network/AWS/CloudWatchEvents/Types/Sum.hs b/amazonka-cloudwatch-events/gen/Network/AWS/CloudWatchEvents/Types/Sum.hs
index 3c9508ffdc1..4eed1ea8feb 100644
--- a/amazonka-cloudwatch-events/gen/Network/AWS/CloudWatchEvents/Types/Sum.hs
+++ b/amazonka-cloudwatch-events/gen/Network/AWS/CloudWatchEvents/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText RuleState where
         "disabled" -> pure Disabled
         "enabled" -> pure Enabled
         e -> fromTextError $ "Failure parsing RuleState from value: '" <> e
-           <> "'. Accepted values: DISABLED, ENABLED"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText RuleState where
     toText = \case
diff --git a/amazonka-cloudwatch-logs/gen/Network/AWS/CloudWatchLogs/Types/Sum.hs b/amazonka-cloudwatch-logs/gen/Network/AWS/CloudWatchLogs/Types/Sum.hs
index dd7d77dc78d..03aff1ab481 100644
--- a/amazonka-cloudwatch-logs/gen/Network/AWS/CloudWatchLogs/Types/Sum.hs
+++ b/amazonka-cloudwatch-logs/gen/Network/AWS/CloudWatchLogs/Types/Sum.hs
@@ -37,7 +37,7 @@ instance FromText ExportTaskStatusCode where
         "pending_cancel" -> pure PendingCancel
         "running" -> pure Running
         e -> fromTextError $ "Failure parsing ExportTaskStatusCode from value: '" <> e
-           <> "'. Accepted values: CANCELLED, COMPLETED, FAILED, PENDING, PENDING_CANCEL, RUNNING"
+           <> "'. Accepted values: cancelled, completed, failed, pending, pending_cancel, running"
 
 instance ToText ExportTaskStatusCode where
     toText = \case
@@ -70,7 +70,7 @@ instance FromText OrderBy where
         "lasteventtime" -> pure LastEventTime
         "logstreamname" -> pure LogStreamName
         e -> fromTextError $ "Failure parsing OrderBy from value: '" <> e
-           <> "'. Accepted values: LastEventTime, LogStreamName"
+           <> "'. Accepted values: lasteventtime, logstreamname"
 
 instance ToText OrderBy where
     toText = \case
diff --git a/amazonka-cloudwatch/gen/Network/AWS/CloudWatch/Types/Sum.hs b/amazonka-cloudwatch/gen/Network/AWS/CloudWatch/Types/Sum.hs
index 2ea9581b812..85f27b371be 100644
--- a/amazonka-cloudwatch/gen/Network/AWS/CloudWatch/Types/Sum.hs
+++ b/amazonka-cloudwatch/gen/Network/AWS/CloudWatch/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText ComparisonOperator where
         "lessthanorequaltothreshold" -> pure LessThanOrEqualToThreshold
         "lessthanthreshold" -> pure LessThanThreshold
         e -> fromTextError $ "Failure parsing ComparisonOperator from value: '" <> e
-           <> "'. Accepted values: GreaterThanOrEqualToThreshold, GreaterThanThreshold, LessThanOrEqualToThreshold, LessThanThreshold"
+           <> "'. Accepted values: greaterthanorequaltothreshold, greaterthanthreshold, lessthanorequaltothreshold, lessthanthreshold"
 
 instance ToText ComparisonOperator where
     toText = \case
@@ -63,7 +63,7 @@ instance FromText HistoryItemType where
         "configurationupdate" -> pure ConfigurationUpdate
         "stateupdate" -> pure StateUpdate
         e -> fromTextError $ "Failure parsing HistoryItemType from value: '" <> e
-           <> "'. Accepted values: Action, ConfigurationUpdate, StateUpdate"
+           <> "'. Accepted values: action, configurationupdate, stateupdate"
 
 instance ToText HistoryItemType where
     toText = \case
@@ -140,7 +140,7 @@ instance FromText StandardUnit where
         "terabytes" -> pure Terabytes
         "terabytes/second" -> pure TerabytesSecond
         e -> fromTextError $ "Failure parsing StandardUnit from value: '" <> e
-           <> "'. Accepted values: Bits, Bits/Second, Bytes, Bytes/Second, Count, Count/Second, Gigabits, Gigabits/Second, Gigabytes, Gigabytes/Second, Kilobits, Kilobits/Second, Kilobytes, Kilobytes/Second, Megabits, Megabits/Second, Megabytes, Megabytes/Second, Microseconds, Milliseconds, None, Percent, Seconds, Terabits, Terabits/Second, Terabytes, Terabytes/Second"
+           <> "'. Accepted values: bits, bits/second, bytes, bytes/second, count, count/second, gigabits, gigabits/second, gigabytes, gigabytes/second, kilobits, kilobits/second, kilobytes, kilobytes/second, megabits, megabits/second, megabytes, megabytes/second, microseconds, milliseconds, none, percent, seconds, terabits, terabits/second, terabytes, terabytes/second"
 
 instance ToText StandardUnit where
     toText = \case
@@ -193,7 +193,7 @@ instance FromText StateValue where
         "insufficient_data" -> pure InsufficientData
         "ok" -> pure OK
         e -> fromTextError $ "Failure parsing StateValue from value: '" <> e
-           <> "'. Accepted values: ALARM, INSUFFICIENT_DATA, OK"
+           <> "'. Accepted values: alarm, insufficient_data, ok"
 
 instance ToText StateValue where
     toText = \case
@@ -226,7 +226,7 @@ instance FromText Statistic where
         "samplecount" -> pure SampleCount
         "sum" -> pure Sum
         e -> fromTextError $ "Failure parsing Statistic from value: '" <> e
-           <> "'. Accepted values: Average, Maximum, Minimum, SampleCount, Sum"
+           <> "'. Accepted values: average, maximum, minimum, samplecount, sum"
 
 instance ToText Statistic where
     toText = \case
diff --git a/amazonka-codecommit/gen/Network/AWS/CodeCommit/Types/Sum.hs b/amazonka-codecommit/gen/Network/AWS/CodeCommit/Types/Sum.hs
index 7fcea6edd83..074971ae2ad 100644
--- a/amazonka-codecommit/gen/Network/AWS/CodeCommit/Types/Sum.hs
+++ b/amazonka-codecommit/gen/Network/AWS/CodeCommit/Types/Sum.hs
@@ -59,7 +59,7 @@ instance FromText RepositoryTriggerEventEnum where
         "deletereference" -> pure DeleteReference
         "updatereference" -> pure UpdateReference
         e -> fromTextError $ "Failure parsing RepositoryTriggerEventEnum from value: '" <> e
-           <> "'. Accepted values: all, createReference, deleteReference, updateReference"
+           <> "'. Accepted values: all, createreference, deletereference, updatereference"
 
 instance ToText RepositoryTriggerEventEnum where
     toText = \case
@@ -90,7 +90,7 @@ instance FromText SortByEnum where
         "lastmodifieddate" -> pure LastModifiedDate
         "repositoryname" -> pure RepositoryName
         e -> fromTextError $ "Failure parsing SortByEnum from value: '" <> e
-           <> "'. Accepted values: lastModifiedDate, repositoryName"
+           <> "'. Accepted values: lastmodifieddate, repositoryname"
 
 instance ToText SortByEnum where
     toText = \case
diff --git a/amazonka-codedeploy/gen/Network/AWS/CodeDeploy/Types/Sum.hs b/amazonka-codedeploy/gen/Network/AWS/CodeDeploy/Types/Sum.hs
index 1ac958febbb..8b51afca9a9 100644
--- a/amazonka-codedeploy/gen/Network/AWS/CodeDeploy/Types/Sum.hs
+++ b/amazonka-codedeploy/gen/Network/AWS/CodeDeploy/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText ApplicationRevisionSortBy where
         "lastusedtime" -> pure LastUsedTime
         "registertime" -> pure RegisterTime
         e -> fromTextError $ "Failure parsing ApplicationRevisionSortBy from value: '" <> e
-           <> "'. Accepted values: firstUsedTime, lastUsedTime, registerTime"
+           <> "'. Accepted values: firstusedtime, lastusedtime, registertime"
 
 instance ToText ApplicationRevisionSortBy where
     toText = \case
@@ -112,7 +112,7 @@ instance FromText DeployErrorCode where
         "throttled" -> pure Throttled
         "timeout" -> pure Timeout
         e -> fromTextError $ "Failure parsing DeployErrorCode from value: '" <> e
-           <> "'. Accepted values: APPLICATION_MISSING, DEPLOYMENT_GROUP_MISSING, HEALTH_CONSTRAINTS, HEALTH_CONSTRAINTS_INVALID, IAM_ROLE_MISSING, IAM_ROLE_PERMISSIONS, INTERNAL_ERROR, NO_EC2_SUBSCRIPTION, NO_INSTANCES, OVER_MAX_INSTANCES, REVISION_MISSING, THROTTLED, TIMEOUT"
+           <> "'. Accepted values: application_missing, deployment_group_missing, health_constraints, health_constraints_invalid, iam_role_missing, iam_role_permissions, internal_error, no_ec2_subscription, no_instances, over_max_instances, revision_missing, throttled, timeout"
 
 instance ToText DeployErrorCode where
     toText = \case
@@ -183,7 +183,7 @@ instance FromText DeploymentStatus where
         "stopped" -> pure Stopped
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing DeploymentStatus from value: '" <> e
-           <> "'. Accepted values: Created, Failed, InProgress, Queued, Stopped, Succeeded"
+           <> "'. Accepted values: created, failed, inprogress, queued, stopped, succeeded"
 
 instance ToText DeploymentStatus where
     toText = \case
@@ -218,7 +218,7 @@ instance FromText EC2TagFilterType where
         "key_only" -> pure KeyOnly
         "value_only" -> pure ValueOnly
         e -> fromTextError $ "Failure parsing EC2TagFilterType from value: '" <> e
-           <> "'. Accepted values: KEY_AND_VALUE, KEY_ONLY, VALUE_ONLY"
+           <> "'. Accepted values: key_and_value, key_only, value_only"
 
 instance ToText EC2TagFilterType where
     toText = \case
@@ -256,7 +256,7 @@ instance FromText InstanceStatus where
         "succeeded" -> pure ISSucceeded
         "unknown" -> pure ISUnknown
         e -> fromTextError $ "Failure parsing InstanceStatus from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Pending, Skipped, Succeeded, Unknown"
+           <> "'. Accepted values: failed, inprogress, pending, skipped, succeeded, unknown"
 
 instance ToText InstanceStatus where
     toText = \case
@@ -297,7 +297,7 @@ instance FromText LifecycleErrorCode where
         "success" -> pure Success
         "unknownerror" -> pure UnknownError
         e -> fromTextError $ "Failure parsing LifecycleErrorCode from value: '" <> e
-           <> "'. Accepted values: ScriptFailed, ScriptMissing, ScriptNotExecutable, ScriptTimedOut, Success, UnknownError"
+           <> "'. Accepted values: scriptfailed, scriptmissing, scriptnotexecutable, scripttimedout, success, unknownerror"
 
 instance ToText LifecycleErrorCode where
     toText = \case
@@ -335,7 +335,7 @@ instance FromText LifecycleEventStatus where
         "succeeded" -> pure LESSucceeded
         "unknown" -> pure LESUnknown
         e -> fromTextError $ "Failure parsing LifecycleEventStatus from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Pending, Skipped, Succeeded, Unknown"
+           <> "'. Accepted values: failed, inprogress, pending, skipped, succeeded, unknown"
 
 instance ToText LifecycleEventStatus where
     toText = \case
@@ -394,7 +394,7 @@ instance FromText MinimumHealthyHostsType where
         "fleet_percent" -> pure FleetPercent
         "host_count" -> pure HostCount
         e -> fromTextError $ "Failure parsing MinimumHealthyHostsType from value: '" <> e
-           <> "'. Accepted values: FLEET_PERCENT, HOST_COUNT"
+           <> "'. Accepted values: fleet_percent, host_count"
 
 instance ToText MinimumHealthyHostsType where
     toText = \case
@@ -423,7 +423,7 @@ instance FromText RegistrationStatus where
         "deregistered" -> pure Deregistered
         "registered" -> pure Registered
         e -> fromTextError $ "Failure parsing RegistrationStatus from value: '" <> e
-           <> "'. Accepted values: Deregistered, Registered"
+           <> "'. Accepted values: deregistered, registered"
 
 instance ToText RegistrationStatus where
     toText = \case
@@ -449,7 +449,7 @@ instance FromText RevisionLocationType where
         "github" -> pure GitHub
         "s3" -> pure S3
         e -> fromTextError $ "Failure parsing RevisionLocationType from value: '" <> e
-           <> "'. Accepted values: GitHub, S3"
+           <> "'. Accepted values: github, s3"
 
 instance ToText RevisionLocationType where
     toText = \case
@@ -504,7 +504,7 @@ instance FromText StopStatus where
         "pending" -> pure SSPending
         "succeeded" -> pure SSSucceeded
         e -> fromTextError $ "Failure parsing StopStatus from value: '" <> e
-           <> "'. Accepted values: Pending, Succeeded"
+           <> "'. Accepted values: pending, succeeded"
 
 instance ToText StopStatus where
     toText = \case
@@ -532,7 +532,7 @@ instance FromText TagFilterType where
         "key_only" -> pure TFTKeyOnly
         "value_only" -> pure TFTValueOnly
         e -> fromTextError $ "Failure parsing TagFilterType from value: '" <> e
-           <> "'. Accepted values: KEY_AND_VALUE, KEY_ONLY, VALUE_ONLY"
+           <> "'. Accepted values: key_and_value, key_only, value_only"
 
 instance ToText TagFilterType where
     toText = \case
@@ -572,7 +572,7 @@ instance FromText TriggerEventType where
         "instancestart" -> pure InstanceStart
         "instancesuccess" -> pure InstanceSuccess
         e -> fromTextError $ "Failure parsing TriggerEventType from value: '" <> e
-           <> "'. Accepted values: DeploymentFailure, DeploymentStart, DeploymentStop, DeploymentSuccess, InstanceFailure, InstanceStart, InstanceSuccess"
+           <> "'. Accepted values: deploymentfailure, deploymentstart, deploymentstop, deploymentsuccess, instancefailure, instancestart, instancesuccess"
 
 instance ToText TriggerEventType where
     toText = \case
diff --git a/amazonka-codepipeline/gen/Network/AWS/CodePipeline/Types/Sum.hs b/amazonka-codepipeline/gen/Network/AWS/CodePipeline/Types/Sum.hs
index 7c7ab405602..78abef83291 100644
--- a/amazonka-codepipeline/gen/Network/AWS/CodePipeline/Types/Sum.hs
+++ b/amazonka-codepipeline/gen/Network/AWS/CodePipeline/Types/Sum.hs
@@ -37,7 +37,7 @@ instance FromText ActionCategory where
         "source" -> pure Source
         "test" -> pure Test
         e -> fromTextError $ "Failure parsing ActionCategory from value: '" <> e
-           <> "'. Accepted values: Approval, Build, Deploy, Invoke, Source, Test"
+           <> "'. Accepted values: approval, build, deploy, invoke, source, test"
 
 instance ToText ActionCategory where
     toText = \case
@@ -72,7 +72,7 @@ instance FromText ActionConfigurationPropertyType where
         "number" -> pure Number
         "string" -> pure String
         e -> fromTextError $ "Failure parsing ActionConfigurationPropertyType from value: '" <> e
-           <> "'. Accepted values: Boolean, Number, String"
+           <> "'. Accepted values: boolean, number, string"
 
 instance ToText ActionConfigurationPropertyType where
     toText = \case
@@ -104,7 +104,7 @@ instance FromText ActionExecutionStatus where
         "inprogress" -> pure InProgress
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing ActionExecutionStatus from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Succeeded"
+           <> "'. Accepted values: failed, inprogress, succeeded"
 
 instance ToText ActionExecutionStatus where
     toText = \case
@@ -133,7 +133,7 @@ instance FromText ActionOwner where
         "custom" -> pure Custom
         "thirdparty" -> pure ThirdParty
         e -> fromTextError $ "Failure parsing ActionOwner from value: '" <> e
-           <> "'. Accepted values: AWS, Custom, ThirdParty"
+           <> "'. Accepted values: aws, custom, thirdparty"
 
 instance ToText ActionOwner where
     toText = \case
@@ -163,7 +163,7 @@ instance FromText ApprovalStatus where
         "approved" -> pure Approved
         "rejected" -> pure Rejected
         e -> fromTextError $ "Failure parsing ApprovalStatus from value: '" <> e
-           <> "'. Accepted values: Approved, Rejected"
+           <> "'. Accepted values: approved, rejected"
 
 instance ToText ApprovalStatus where
     toText = \case
@@ -187,7 +187,7 @@ instance FromText ArtifactLocationType where
     parser = takeLowerText >>= \case
         "s3" -> pure ALTS3
         e -> fromTextError $ "Failure parsing ArtifactLocationType from value: '" <> e
-           <> "'. Accepted values: S3"
+           <> "'. Accepted values: s3"
 
 instance ToText ArtifactLocationType where
     toText = \case
@@ -210,7 +210,7 @@ instance FromText ArtifactStoreType where
     parser = takeLowerText >>= \case
         "s3" -> pure S3
         e -> fromTextError $ "Failure parsing ArtifactStoreType from value: '" <> e
-           <> "'. Accepted values: S3"
+           <> "'. Accepted values: s3"
 
 instance ToText ArtifactStoreType where
     toText = \case
@@ -236,7 +236,7 @@ instance FromText BlockerType where
     parser = takeLowerText >>= \case
         "schedule" -> pure Schedule
         e -> fromTextError $ "Failure parsing BlockerType from value: '" <> e
-           <> "'. Accepted values: Schedule"
+           <> "'. Accepted values: schedule"
 
 instance ToText BlockerType where
     toText = \case
@@ -262,7 +262,7 @@ instance FromText EncryptionKeyType where
     parser = takeLowerText >>= \case
         "kms" -> pure KMS
         e -> fromTextError $ "Failure parsing EncryptionKeyType from value: '" <> e
-           <> "'. Accepted values: KMS"
+           <> "'. Accepted values: kms"
 
 instance ToText EncryptionKeyType where
     toText = \case
@@ -298,7 +298,7 @@ instance FromText FailureType where
         "revisionunavailable" -> pure RevisionUnavailable
         "systemunavailable" -> pure SystemUnavailable
         e -> fromTextError $ "Failure parsing FailureType from value: '" <> e
-           <> "'. Accepted values: ConfigurationError, JobFailed, PermissionError, RevisionOutOfSync, RevisionUnavailable, SystemUnavailable"
+           <> "'. Accepted values: configurationerror, jobfailed, permissionerror, revisionoutofsync, revisionunavailable, systemunavailable"
 
 instance ToText FailureType where
     toText = \case
@@ -338,7 +338,7 @@ instance FromText JobStatus where
         "succeeded" -> pure JSSucceeded
         "timedout" -> pure JSTimedOut
         e -> fromTextError $ "Failure parsing JobStatus from value: '" <> e
-           <> "'. Accepted values: Created, Dispatched, Failed, InProgress, Queued, Succeeded, TimedOut"
+           <> "'. Accepted values: created, dispatched, failed, inprogress, queued, succeeded, timedout"
 
 instance ToText JobStatus where
     toText = \case
@@ -371,7 +371,7 @@ instance FromText StageExecutionStatus where
         "inprogress" -> pure SESInProgress
         "succeeded" -> pure SESSucceeded
         e -> fromTextError $ "Failure parsing StageExecutionStatus from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Succeeded"
+           <> "'. Accepted values: failed, inprogress, succeeded"
 
 instance ToText StageExecutionStatus where
     toText = \case
@@ -396,7 +396,7 @@ instance FromText StageRetryMode where
     parser = takeLowerText >>= \case
         "failed_actions" -> pure FailedActions
         e -> fromTextError $ "Failure parsing StageRetryMode from value: '" <> e
-           <> "'. Accepted values: FAILED_ACTIONS"
+           <> "'. Accepted values: failed_actions"
 
 instance ToText StageRetryMode where
     toText = \case
@@ -421,7 +421,7 @@ instance FromText StageTransitionType where
         "inbound" -> pure Inbound
         "outbound" -> pure Outbound
         e -> fromTextError $ "Failure parsing StageTransitionType from value: '" <> e
-           <> "'. Accepted values: Inbound, Outbound"
+           <> "'. Accepted values: inbound, outbound"
 
 instance ToText StageTransitionType where
     toText = \case
diff --git a/amazonka-cognito-identity/gen/Network/AWS/CognitoIdentity/Types/Sum.hs b/amazonka-cognito-identity/gen/Network/AWS/CognitoIdentity/Types/Sum.hs
index f9f6e89eea0..d9778744d03 100644
--- a/amazonka-cognito-identity/gen/Network/AWS/CognitoIdentity/Types/Sum.hs
+++ b/amazonka-cognito-identity/gen/Network/AWS/CognitoIdentity/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText CognitoErrorCode where
         "accessdenied" -> pure AccessDenied
         "internalservererror" -> pure InternalServerError
         e -> fromTextError $ "Failure parsing CognitoErrorCode from value: '" <> e
-           <> "'. Accepted values: AccessDenied, InternalServerError"
+           <> "'. Accepted values: accessdenied, internalservererror"
 
 instance ToText CognitoErrorCode where
     toText = \case
diff --git a/amazonka-cognito-idp/gen/Network/AWS/CognitoIdentityProvider/Types/Sum.hs b/amazonka-cognito-idp/gen/Network/AWS/CognitoIdentityProvider/Types/Sum.hs
index ddb7290dd7e..f6a2efe26ae 100644
--- a/amazonka-cognito-idp/gen/Network/AWS/CognitoIdentityProvider/Types/Sum.hs
+++ b/amazonka-cognito-idp/gen/Network/AWS/CognitoIdentityProvider/Types/Sum.hs
@@ -65,7 +65,7 @@ instance FromText AttributeDataType where
         "number" -> pure Number
         "string" -> pure String
         e -> fromTextError $ "Failure parsing AttributeDataType from value: '" <> e
-           <> "'. Accepted values: Boolean, DateTime, Number, String"
+           <> "'. Accepted values: boolean, datetime, number, string"
 
 instance ToText AttributeDataType where
     toText = \case
@@ -100,7 +100,7 @@ instance FromText AuthFlowType where
         "refresh_token_auth" -> pure RefreshTokenAuth
         "user_srp_auth" -> pure UserSrpAuth
         e -> fromTextError $ "Failure parsing AuthFlowType from value: '" <> e
-           <> "'. Accepted values: ADMIN_NO_SRP_AUTH, CUSTOM_AUTH, REFRESH_TOKEN_AUTH, USER_SRP_AUTH"
+           <> "'. Accepted values: admin_no_srp_auth, custom_auth, refresh_token_auth, user_srp_auth"
 
 instance ToText AuthFlowType where
     toText = \case
@@ -136,7 +136,7 @@ instance FromText ChallengeNameType where
         "password_verifier" -> pure CNTPasswordVerifier
         "sms_mfa" -> pure CNTSmsMFA
         e -> fromTextError $ "Failure parsing ChallengeNameType from value: '" <> e
-           <> "'. Accepted values: ADMIN_NO_SRP_AUTH, CUSTOM_CHALLENGE, DEVICE_PASSWORD_VERIFIER, DEVICE_SRP_AUTH, PASSWORD_VERIFIER, SMS_MFA"
+           <> "'. Accepted values: admin_no_srp_auth, custom_challenge, device_password_verifier, device_srp_auth, password_verifier, sms_mfa"
 
 instance ToText ChallengeNameType where
     toText = \case
@@ -169,7 +169,7 @@ instance FromText DeliveryMediumType where
         "email" -> pure DMTEmail
         "sms" -> pure DMTSms
         e -> fromTextError $ "Failure parsing DeliveryMediumType from value: '" <> e
-           <> "'. Accepted values: EMAIL, SMS"
+           <> "'. Accepted values: email, sms"
 
 instance ToText DeliveryMediumType where
     toText = \case
@@ -222,7 +222,7 @@ instance FromText ExplicitAuthFlowsType where
     parser = takeLowerText >>= \case
         "admin_no_srp_auth" -> pure EAFTAdminNoSrpAuth
         e -> fromTextError $ "Failure parsing ExplicitAuthFlowsType from value: '" <> e
-           <> "'. Accepted values: ADMIN_NO_SRP_AUTH"
+           <> "'. Accepted values: admin_no_srp_auth"
 
 instance ToText ExplicitAuthFlowsType where
     toText = \case
@@ -250,7 +250,7 @@ instance FromText StatusType where
         "disabled" -> pure Disabled
         "enabled" -> pure Enabled
         e -> fromTextError $ "Failure parsing StatusType from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText StatusType where
     toText = \case
@@ -278,7 +278,7 @@ instance FromText UserPoolMFAType where
         "off" -> pure Off
         "optional" -> pure Optional
         e -> fromTextError $ "Failure parsing UserPoolMFAType from value: '" <> e
-           <> "'. Accepted values: ON, OFF, OPTIONAL"
+           <> "'. Accepted values: on, off, optional"
 
 instance ToText UserPoolMFAType where
     toText = \case
@@ -316,7 +316,7 @@ instance FromText UserStatusType where
         "unconfirmed" -> pure Unconfirmed
         "unknown" -> pure Unknown
         e -> fromTextError $ "Failure parsing UserStatusType from value: '" <> e
-           <> "'. Accepted values: ARCHIVED, COMPROMISED, CONFIRMED, RESET_REQUIRED, UNCONFIRMED, UNKNOWN"
+           <> "'. Accepted values: archived, compromised, confirmed, reset_required, unconfirmed, unknown"
 
 instance ToText UserStatusType where
     toText = \case
diff --git a/amazonka-cognito-sync/gen/Network/AWS/CognitoSync/Types/Sum.hs b/amazonka-cognito-sync/gen/Network/AWS/CognitoSync/Types/Sum.hs
index f358961a540..ddf034b029e 100644
--- a/amazonka-cognito-sync/gen/Network/AWS/CognitoSync/Types/Sum.hs
+++ b/amazonka-cognito-sync/gen/Network/AWS/CognitoSync/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText BulkPublishStatus where
         "not_started" -> pure NotStarted
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing BulkPublishStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, IN_PROGRESS, NOT_STARTED, SUCCEEDED"
+           <> "'. Accepted values: failed, in_progress, not_started, succeeded"
 
 instance ToText BulkPublishStatus where
     toText = \case
@@ -91,7 +91,7 @@ instance FromText Platform where
         "apns_sandbox" -> pure APNSSandbox
         "gcm" -> pure GCM
         e -> fromTextError $ "Failure parsing Platform from value: '" <> e
-           <> "'. Accepted values: ADM, APNS, APNS_SANDBOX, GCM"
+           <> "'. Accepted values: adm, apns, apns_sandbox, gcm"
 
 instance ToText Platform where
     toText = \case
@@ -119,7 +119,7 @@ instance FromText StreamingStatus where
         "disabled" -> pure Disabled
         "enabled" -> pure Enabled
         e -> fromTextError $ "Failure parsing StreamingStatus from value: '" <> e
-           <> "'. Accepted values: DISABLED, ENABLED"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText StreamingStatus where
     toText = \case
diff --git a/amazonka-config/gen/Network/AWS/Config/Types/Sum.hs b/amazonka-config/gen/Network/AWS/Config/Types/Sum.hs
index facd283a996..ebab156df37 100644
--- a/amazonka-config/gen/Network/AWS/Config/Types/Sum.hs
+++ b/amazonka-config/gen/Network/AWS/Config/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText ChronologicalOrder where
         "forward" -> pure Forward
         "reverse" -> pure Reverse
         e -> fromTextError $ "Failure parsing ChronologicalOrder from value: '" <> e
-           <> "'. Accepted values: Forward, Reverse"
+           <> "'. Accepted values: forward, reverse"
 
 instance ToText ChronologicalOrder where
     toText = \case
@@ -59,7 +59,7 @@ instance FromText ComplianceType where
         "non_compliant" -> pure NonCompliant
         "not_applicable" -> pure NotApplicable
         e -> fromTextError $ "Failure parsing ComplianceType from value: '" <> e
-           <> "'. Accepted values: COMPLIANT, INSUFFICIENT_DATA, NON_COMPLIANT, NOT_APPLICABLE"
+           <> "'. Accepted values: compliant, insufficient_data, non_compliant, not_applicable"
 
 instance ToText ComplianceType where
     toText = \case
@@ -94,7 +94,7 @@ instance FromText ConfigRuleState where
         "deleting_results" -> pure DeletingResults
         "evaluating" -> pure Evaluating
         e -> fromTextError $ "Failure parsing ConfigRuleState from value: '" <> e
-           <> "'. Accepted values: ACTIVE, DELETING, DELETING_RESULTS, EVALUATING"
+           <> "'. Accepted values: active, deleting, deleting_results, evaluating"
 
 instance ToText ConfigRuleState where
     toText = \case
@@ -129,7 +129,7 @@ instance FromText ConfigurationItemStatus where
         "failed" -> pure Failed
         "ok" -> pure OK
         e -> fromTextError $ "Failure parsing ConfigurationItemStatus from value: '" <> e
-           <> "'. Accepted values: Deleted, Discovered, Failed, Ok"
+           <> "'. Accepted values: deleted, discovered, failed, ok"
 
 instance ToText ConfigurationItemStatus where
     toText = \case
@@ -159,7 +159,7 @@ instance FromText DeliveryStatus where
         "not_applicable" -> pure DSNotApplicable
         "success" -> pure DSSuccess
         e -> fromTextError $ "Failure parsing DeliveryStatus from value: '" <> e
-           <> "'. Accepted values: Failure, Not_Applicable, Success"
+           <> "'. Accepted values: failure, not_applicable, success"
 
 instance ToText DeliveryStatus where
     toText = \case
@@ -218,7 +218,7 @@ instance FromText MaximumExecutionFrequency where
         "twelve_hours" -> pure TwelveHours
         "twentyfour_hours" -> pure TwentyFourHours
         e -> fromTextError $ "Failure parsing MaximumExecutionFrequency from value: '" <> e
-           <> "'. Accepted values: One_Hour, Six_Hours, Three_Hours, Twelve_Hours, TwentyFour_Hours"
+           <> "'. Accepted values: one_hour, six_hours, three_hours, twelve_hours, twentyfour_hours"
 
 instance ToText MaximumExecutionFrequency where
     toText = \case
@@ -252,7 +252,7 @@ instance FromText MessageType where
         "configurationsnapshotdeliverycompleted" -> pure ConfigurationSnapshotDeliveryCompleted
         "schedulednotification" -> pure ScheduledNotification
         e -> fromTextError $ "Failure parsing MessageType from value: '" <> e
-           <> "'. Accepted values: ConfigurationItemChangeNotification, ConfigurationSnapshotDeliveryCompleted, ScheduledNotification"
+           <> "'. Accepted values: configurationitemchangenotification, configurationsnapshotdeliverycompleted, schedulednotification"
 
 instance ToText MessageType where
     toText = \case
@@ -282,7 +282,7 @@ instance FromText Owner where
         "aws" -> pure AWS
         "custom_lambda" -> pure CustomLambda
         e -> fromTextError $ "Failure parsing Owner from value: '" <> e
-           <> "'. Accepted values: AWS, CUSTOM_LAMBDA"
+           <> "'. Accepted values: aws, custom_lambda"
 
 instance ToText Owner where
     toText = \case
@@ -313,7 +313,7 @@ instance FromText RecorderStatus where
         "pending" -> pure Pending
         "success" -> pure Success
         e -> fromTextError $ "Failure parsing RecorderStatus from value: '" <> e
-           <> "'. Accepted values: Failure, Pending, Success"
+           <> "'. Accepted values: failure, pending, success"
 
 instance ToText RecorderStatus where
     toText = \case
@@ -386,7 +386,7 @@ instance FromText ResourceType where
         "aws::rds::dbsubnetgroup" -> pure AWSRDSDBSubnetGroup
         "aws::rds::eventsubscription" -> pure AWSRDSEventSubscription
         e -> fromTextError $ "Failure parsing ResourceType from value: '" <> e
-           <> "'. Accepted values: AWS::ACM::Certificate, AWS::CloudTrail::Trail, AWS::EC2::CustomerGateway, AWS::EC2::EIP, AWS::EC2::Host, AWS::EC2::Instance, AWS::EC2::InternetGateway, AWS::EC2::NetworkAcl, AWS::EC2::NetworkInterface, AWS::EC2::RouteTable, AWS::EC2::SecurityGroup, AWS::EC2::Subnet, AWS::EC2::VPC, AWS::EC2::VPNConnection, AWS::EC2::VPNGateway, AWS::EC2::Volume, AWS::IAM::Group, AWS::IAM::Policy, AWS::IAM::Role, AWS::IAM::User, AWS::RDS::DBInstance, AWS::RDS::DBSecurityGroup, AWS::RDS::DBSnapshot, AWS::RDS::DBSubnetGroup, AWS::RDS::EventSubscription"
+           <> "'. Accepted values: aws::acm::certificate, aws::cloudtrail::trail, aws::ec2::customergateway, aws::ec2::eip, aws::ec2::host, aws::ec2::instance, aws::ec2::internetgateway, aws::ec2::networkacl, aws::ec2::networkinterface, aws::ec2::routetable, aws::ec2::securitygroup, aws::ec2::subnet, aws::ec2::vpc, aws::ec2::vpnconnection, aws::ec2::vpngateway, aws::ec2::volume, aws::iam::group, aws::iam::policy, aws::iam::role, aws::iam::user, aws::rds::dbinstance, aws::rds::dbsecuritygroup, aws::rds::dbsnapshot, aws::rds::dbsubnetgroup, aws::rds::eventsubscription"
 
 instance ToText ResourceType where
     toText = \case
diff --git a/amazonka-datapipeline/gen/Network/AWS/DataPipeline/Types/Sum.hs b/amazonka-datapipeline/gen/Network/AWS/DataPipeline/Types/Sum.hs
index f01d7a0a021..ca37a1d5952 100644
--- a/amazonka-datapipeline/gen/Network/AWS/DataPipeline/Types/Sum.hs
+++ b/amazonka-datapipeline/gen/Network/AWS/DataPipeline/Types/Sum.hs
@@ -35,7 +35,7 @@ instance FromText OperatorType where
         "le" -> pure OperatorLE
         "ref_eq" -> pure OperatorRefEQ
         e -> fromTextError $ "Failure parsing OperatorType from value: '" <> e
-           <> "'. Accepted values: BETWEEN, EQ, GE, LE, REF_EQ"
+           <> "'. Accepted values: between, eq, ge, le, ref_eq"
 
 instance ToText OperatorType where
     toText = \case
@@ -66,7 +66,7 @@ instance FromText TaskStatus where
         "false" -> pure False'
         "finished" -> pure Finished
         e -> fromTextError $ "Failure parsing TaskStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, FALSE, FINISHED"
+           <> "'. Accepted values: failed, false, finished"
 
 instance ToText TaskStatus where
     toText = \case
diff --git a/amazonka-devicefarm/gen/Network/AWS/DeviceFarm/Types/Sum.hs b/amazonka-devicefarm/gen/Network/AWS/DeviceFarm/Types/Sum.hs
index e0d1a6da77d..7c40504c8af 100644
--- a/amazonka-devicefarm/gen/Network/AWS/DeviceFarm/Types/Sum.hs
+++ b/amazonka-devicefarm/gen/Network/AWS/DeviceFarm/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText ArtifactCategory where
         "log" -> pure ACLog
         "screenshot" -> pure ACScreenshot
         e -> fromTextError $ "Failure parsing ArtifactCategory from value: '" <> e
-           <> "'. Accepted values: FILE, LOG, SCREENSHOT"
+           <> "'. Accepted values: file, log, screenshot"
 
 instance ToText ArtifactCategory where
     toText = \case
@@ -104,7 +104,7 @@ instance FromText ArtifactType where
         "webkit_log" -> pure WebkitLog
         "xctest_log" -> pure XctestLog
         e -> fromTextError $ "Failure parsing ArtifactType from value: '" <> e
-           <> "'. Accepted values: APPIUM_JAVA_OUTPUT, APPIUM_JAVA_XML_OUTPUT, APPIUM_PYTHON_OUTPUT, APPIUM_PYTHON_XML_OUTPUT, APPIUM_SERVER_OUTPUT, APPLICATION_CRASH_REPORT, AUTOMATION_OUTPUT, CALABASH_JSON_OUTPUT, CALABASH_JAVA_XML_OUTPUT, CALABASH_PRETTY_OUTPUT, CALABASH_STANDARD_OUTPUT, DEVICE_LOG, EXERCISER_MONKEY_OUTPUT, EXPLORER_EVENT_LOG, EXPLORER_SUMMARY_LOG, INSTRUMENTATION_OUTPUT, MESSAGE_LOG, RESULT_LOG, SCREENSHOT, SERVICE_LOG, UNKNOWN, VIDEO, VIDEO_LOG, WEBKIT_LOG, XCTEST_LOG"
+           <> "'. Accepted values: appium_java_output, appium_java_xml_output, appium_python_output, appium_python_xml_output, appium_server_output, application_crash_report, automation_output, calabash_json_output, calabash_java_xml_output, calabash_pretty_output, calabash_standard_output, device_log, exerciser_monkey_output, explorer_event_log, explorer_summary_log, instrumentation_output, message_log, result_log, screenshot, service_log, unknown, video, video_log, webkit_log, xctest_log"
 
 instance ToText ArtifactType where
     toText = \case
@@ -153,7 +153,7 @@ instance FromText BillingMethod where
         "metered" -> pure Metered
         "unmetered" -> pure Unmetered
         e -> fromTextError $ "Failure parsing BillingMethod from value: '" <> e
-           <> "'. Accepted values: METERED, UNMETERED"
+           <> "'. Accepted values: metered, unmetered"
 
 instance ToText BillingMethod where
     toText = \case
@@ -180,7 +180,7 @@ instance FromText CurrencyCode where
     parser = takeLowerText >>= \case
         "usd" -> pure Usd
         e -> fromTextError $ "Failure parsing CurrencyCode from value: '" <> e
-           <> "'. Accepted values: USD"
+           <> "'. Accepted values: usd"
 
 instance ToText CurrencyCode where
     toText = \case
@@ -211,7 +211,7 @@ instance FromText DeviceAttribute where
         "platform" -> pure Platform
         "remote_access_enabled" -> pure RemoteAccessEnabled
         e -> fromTextError $ "Failure parsing DeviceAttribute from value: '" <> e
-           <> "'. Accepted values: ARN, FORM_FACTOR, MANUFACTURER, PLATFORM, REMOTE_ACCESS_ENABLED"
+           <> "'. Accepted values: arn, form_factor, manufacturer, platform, remote_access_enabled"
 
 instance ToText DeviceAttribute where
     toText = \case
@@ -243,7 +243,7 @@ instance FromText DeviceFormFactor where
         "phone" -> pure Phone
         "tablet" -> pure Tablet
         e -> fromTextError $ "Failure parsing DeviceFormFactor from value: '" <> e
-           <> "'. Accepted values: PHONE, TABLET"
+           <> "'. Accepted values: phone, tablet"
 
 instance ToText DeviceFormFactor where
     toText = \case
@@ -269,7 +269,7 @@ instance FromText DevicePlatform where
         "android" -> pure Android
         "ios" -> pure Ios
         e -> fromTextError $ "Failure parsing DevicePlatform from value: '" <> e
-           <> "'. Accepted values: ANDROID, IOS"
+           <> "'. Accepted values: android, ios"
 
 instance ToText DevicePlatform where
     toText = \case
@@ -295,7 +295,7 @@ instance FromText DevicePoolType where
         "curated" -> pure Curated
         "private" -> pure Private
         e -> fromTextError $ "Failure parsing DevicePoolType from value: '" <> e
-           <> "'. Accepted values: CURATED, PRIVATE"
+           <> "'. Accepted values: curated, private"
 
 instance ToText DevicePoolType where
     toText = \case
@@ -334,7 +334,7 @@ instance FromText ExecutionResult where
         "stopped" -> pure ERStopped
         "warned" -> pure ERWarned
         e -> fromTextError $ "Failure parsing ExecutionResult from value: '" <> e
-           <> "'. Accepted values: ERRORED, FAILED, PASSED, PENDING, SKIPPED, STOPPED, WARNED"
+           <> "'. Accepted values: errored, failed, passed, pending, skipped, stopped, warned"
 
 instance ToText ExecutionResult where
     toText = \case
@@ -379,7 +379,7 @@ instance FromText ExecutionStatus where
         "scheduling" -> pure Scheduling
         "stopping" -> pure Stopping
         e -> fromTextError $ "Failure parsing ExecutionStatus from value: '" <> e
-           <> "'. Accepted values: COMPLETED, PENDING, PENDING_CONCURRENCY, PENDING_DEVICE, PREPARING, PROCESSING, RUNNING, SCHEDULING, STOPPING"
+           <> "'. Accepted values: completed, pending, pending_concurrency, pending_device, preparing, processing, running, scheduling, stopping"
 
 instance ToText ExecutionStatus where
     toText = \case
@@ -414,7 +414,7 @@ instance FromText OfferingTransactionType where
         "renew" -> pure Renew
         "system" -> pure System
         e -> fromTextError $ "Failure parsing OfferingTransactionType from value: '" <> e
-           <> "'. Accepted values: PURCHASE, RENEW, SYSTEM"
+           <> "'. Accepted values: purchase, renew, system"
 
 instance ToText OfferingTransactionType where
     toText = \case
@@ -439,7 +439,7 @@ instance FromText OfferingType where
     parser = takeLowerText >>= \case
         "recurring" -> pure Recurring
         e -> fromTextError $ "Failure parsing OfferingType from value: '" <> e
-           <> "'. Accepted values: RECURRING"
+           <> "'. Accepted values: recurring"
 
 instance ToText OfferingType where
     toText = \case
@@ -462,7 +462,7 @@ instance FromText RecurringChargeFrequency where
     parser = takeLowerText >>= \case
         "monthly" -> pure Monthly
         e -> fromTextError $ "Failure parsing RecurringChargeFrequency from value: '" <> e
-           <> "'. Accepted values: MONTHLY"
+           <> "'. Accepted values: monthly"
 
 instance ToText RecurringChargeFrequency where
     toText = \case
@@ -493,7 +493,7 @@ instance FromText RuleOperator where
         "less_than" -> pure LessThan
         "not_in" -> pure NotIn
         e -> fromTextError $ "Failure parsing RuleOperator from value: '" <> e
-           <> "'. Accepted values: EQUALS, GREATER_THAN, IN, LESS_THAN, NOT_IN"
+           <> "'. Accepted values: equals, greater_than, in, less_than, not_in"
 
 instance ToText RuleOperator where
     toText = \case
@@ -555,7 +555,7 @@ instance FromText SampleType where
         "threads" -> pure Threads
         "tx_rate" -> pure TxRate
         e -> fromTextError $ "Failure parsing SampleType from value: '" <> e
-           <> "'. Accepted values: CPU, MEMORY, NATIVE_AVG_DRAWTIME, NATIVE_FPS, NATIVE_FRAMES, NATIVE_MAX_DRAWTIME, NATIVE_MIN_DRAWTIME, OPENGL_AVG_DRAWTIME, OPENGL_FPS, OPENGL_FRAMES, OPENGL_MAX_DRAWTIME, OPENGL_MIN_DRAWTIME, RX, RX_RATE, TX, THREADS, TX_RATE"
+           <> "'. Accepted values: cpu, memory, native_avg_drawtime, native_fps, native_frames, native_max_drawtime, native_min_drawtime, opengl_avg_drawtime, opengl_fps, opengl_frames, opengl_max_drawtime, opengl_min_drawtime, rx, rx_rate, tx, threads, tx_rate"
 
 instance ToText SampleType where
     toText = \case
@@ -620,7 +620,7 @@ instance FromText TestType where
         "xctest" -> pure Xctest
         "xctest_ui" -> pure XctestUi
         e -> fromTextError $ "Failure parsing TestType from value: '" <> e
-           <> "'. Accepted values: APPIUM_JAVA_JUNIT, APPIUM_JAVA_TESTNG, APPIUM_PYTHON, APPIUM_WEB_JAVA_JUNIT, APPIUM_WEB_JAVA_TESTNG, APPIUM_WEB_PYTHON, BUILTIN_EXPLORER, BUILTIN_FUZZ, CALABASH, INSTRUMENTATION, UIAUTOMATION, UIAUTOMATOR, XCTEST, XCTEST_UI"
+           <> "'. Accepted values: appium_java_junit, appium_java_testng, appium_python, appium_web_java_junit, appium_web_java_testng, appium_web_python, builtin_explorer, builtin_fuzz, calabash, instrumentation, uiautomation, uiautomator, xctest, xctest_ui"
 
 instance ToText TestType where
     toText = \case
@@ -665,7 +665,7 @@ instance FromText UploadStatus where
         "processing" -> pure USProcessing
         "succeeded" -> pure USSucceeded
         e -> fromTextError $ "Failure parsing UploadStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, INITIALIZED, PROCESSING, SUCCEEDED"
+           <> "'. Accepted values: failed, initialized, processing, succeeded"
 
 instance ToText UploadStatus where
     toText = \case
@@ -721,7 +721,7 @@ instance FromText UploadType where
         "xctest_test_package" -> pure XctestTestPackage
         "xctest_ui_test_package" -> pure XctestUiTestPackage
         e -> fromTextError $ "Failure parsing UploadType from value: '" <> e
-           <> "'. Accepted values: ANDROID_APP, APPIUM_JAVA_JUNIT_TEST_PACKAGE, APPIUM_JAVA_TESTNG_TEST_PACKAGE, APPIUM_PYTHON_TEST_PACKAGE, APPIUM_WEB_JAVA_JUNIT_TEST_PACKAGE, APPIUM_WEB_JAVA_TESTNG_TEST_PACKAGE, APPIUM_WEB_PYTHON_TEST_PACKAGE, CALABASH_TEST_PACKAGE, EXTERNAL_DATA, INSTRUMENTATION_TEST_PACKAGE, IOS_APP, UIAUTOMATION_TEST_PACKAGE, UIAUTOMATOR_TEST_PACKAGE, WEB_APP, XCTEST_TEST_PACKAGE, XCTEST_UI_TEST_PACKAGE"
+           <> "'. Accepted values: android_app, appium_java_junit_test_package, appium_java_testng_test_package, appium_python_test_package, appium_web_java_junit_test_package, appium_web_java_testng_test_package, appium_web_python_test_package, calabash_test_package, external_data, instrumentation_test_package, ios_app, uiautomation_test_package, uiautomator_test_package, web_app, xctest_test_package, xctest_ui_test_package"
 
 instance ToText UploadType where
     toText = \case
diff --git a/amazonka-discovery/gen/Network/AWS/Discovery/Types/Sum.hs b/amazonka-discovery/gen/Network/AWS/Discovery/Types/Sum.hs
index 65222ae4eac..9a7000639ff 100644
--- a/amazonka-discovery/gen/Network/AWS/Discovery/Types/Sum.hs
+++ b/amazonka-discovery/gen/Network/AWS/Discovery/Types/Sum.hs
@@ -37,7 +37,7 @@ instance FromText AgentStatus where
         "unhealthy" -> pure Unhealthy
         "unknown" -> pure Unknown
         e -> fromTextError $ "Failure parsing AgentStatus from value: '" <> e
-           <> "'. Accepted values: BLACKLISTED, HEALTHY, RUNNING, SHUTDOWN, UNHEALTHY, UNKNOWN"
+           <> "'. Accepted values: blacklisted, healthy, running, shutdown, unhealthy, unknown"
 
 instance ToText AgentStatus where
     toText = \case
@@ -69,7 +69,7 @@ instance FromText ConfigurationItemType where
         "process" -> pure Process
         "server" -> pure Server
         e -> fromTextError $ "Failure parsing ConfigurationItemType from value: '" <> e
-           <> "'. Accepted values: CONNECTION, PROCESS, SERVER"
+           <> "'. Accepted values: connection, process, server"
 
 instance ToText ConfigurationItemType where
     toText = \case
@@ -101,7 +101,7 @@ instance FromText ExportStatus where
         "in_progress" -> pure InProgress
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing ExportStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, IN_PROGRESS, SUCCEEDED"
+           <> "'. Accepted values: failed, in_progress, succeeded"
 
 instance ToText ExportStatus where
     toText = \case
diff --git a/amazonka-ds/gen/Network/AWS/DirectoryService/Types/Sum.hs b/amazonka-ds/gen/Network/AWS/DirectoryService/Types/Sum.hs
index 20d26f59b79..1faf07de796 100644
--- a/amazonka-ds/gen/Network/AWS/DirectoryService/Types/Sum.hs
+++ b/amazonka-ds/gen/Network/AWS/DirectoryService/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText DirectorySize where
         "large" -> pure Large
         "small" -> pure Small
         e -> fromTextError $ "Failure parsing DirectorySize from value: '" <> e
-           <> "'. Accepted values: Large, Small"
+           <> "'. Accepted values: large, small"
 
 instance ToText DirectorySize where
     toText = \case
@@ -76,7 +76,7 @@ instance FromText DirectoryStage where
         "restorefailed" -> pure DSRestoreFailed
         "restoring" -> pure DSRestoring
         e -> fromTextError $ "Failure parsing DirectoryStage from value: '" <> e
-           <> "'. Accepted values: Active, Created, Creating, Deleted, Deleting, Failed, Impaired, Inoperable, Requested, RestoreFailed, Restoring"
+           <> "'. Accepted values: active, created, creating, deleted, deleting, failed, impaired, inoperable, requested, restorefailed, restoring"
 
 instance ToText DirectoryStage where
     toText = \case
@@ -113,7 +113,7 @@ instance FromText DirectoryType where
         "microsoftad" -> pure MicrosoftAD
         "simplead" -> pure SimpleAD
         e -> fromTextError $ "Failure parsing DirectoryType from value: '" <> e
-           <> "'. Accepted values: ADConnector, MicrosoftAD, SimpleAD"
+           <> "'. Accepted values: adconnector, microsoftad, simplead"
 
 instance ToText DirectoryType where
     toText = \case
@@ -148,7 +148,7 @@ instance FromText IPRouteStatusMsg where
         "removed" -> pure Removed
         "removing" -> pure Removing
         e -> fromTextError $ "Failure parsing IPRouteStatusMsg from value: '" <> e
-           <> "'. Accepted values: AddFailed, Added, Adding, RemoveFailed, Removed, Removing"
+           <> "'. Accepted values: addfailed, added, adding, removefailed, removed, removing"
 
 instance ToText IPRouteStatusMsg where
     toText = \case
@@ -182,7 +182,7 @@ instance FromText RadiusAuthenticationProtocol where
         "ms-chapv2" -> pure MsCHAPV2
         "pap" -> pure Pap
         e -> fromTextError $ "Failure parsing RadiusAuthenticationProtocol from value: '" <> e
-           <> "'. Accepted values: CHAP, MS-CHAPv1, MS-CHAPv2, PAP"
+           <> "'. Accepted values: chap, ms-chapv1, ms-chapv2, pap"
 
 instance ToText RadiusAuthenticationProtocol where
     toText = \case
@@ -215,7 +215,7 @@ instance FromText RadiusStatus where
         "creating" -> pure Creating
         "failed" -> pure Failed
         e -> fromTextError $ "Failure parsing RadiusStatus from value: '" <> e
-           <> "'. Accepted values: Completed, Creating, Failed"
+           <> "'. Accepted values: completed, creating, failed"
 
 instance ToText RadiusStatus where
     toText = \case
@@ -240,7 +240,7 @@ instance FromText ReplicationScope where
     parser = takeLowerText >>= \case
         "domain" -> pure Domain
         e -> fromTextError $ "Failure parsing ReplicationScope from value: '" <> e
-           <> "'. Accepted values: Domain"
+           <> "'. Accepted values: domain"
 
 instance ToText ReplicationScope where
     toText = \case
@@ -267,7 +267,7 @@ instance FromText SnapshotStatus where
         "creating" -> pure SSCreating
         "failed" -> pure SSFailed
         e -> fromTextError $ "Failure parsing SnapshotStatus from value: '" <> e
-           <> "'. Accepted values: Completed, Creating, Failed"
+           <> "'. Accepted values: completed, creating, failed"
 
 instance ToText SnapshotStatus where
     toText = \case
@@ -294,7 +294,7 @@ instance FromText SnapshotType where
         "auto" -> pure Auto
         "manual" -> pure Manual
         e -> fromTextError $ "Failure parsing SnapshotType from value: '" <> e
-           <> "'. Accepted values: Auto, Manual"
+           <> "'. Accepted values: auto, manual"
 
 instance ToText SnapshotType where
     toText = \case
@@ -324,7 +324,7 @@ instance FromText TopicStatus where
         "registered" -> pure TRegistered
         "topic not found" -> pure TTopicNotFound
         e -> fromTextError $ "Failure parsing TopicStatus from value: '" <> e
-           <> "'. Accepted values: Deleted, Failed, Registered, Topic not found"
+           <> "'. Accepted values: deleted, failed, registered, topic not found"
 
 instance ToText TopicStatus where
     toText = \case
@@ -354,7 +354,7 @@ instance FromText TrustDirection where
         "one-way: outgoing" -> pure OneWayOutgoing
         "two-way" -> pure TwoWay
         e -> fromTextError $ "Failure parsing TrustDirection from value: '" <> e
-           <> "'. Accepted values: One-Way: Incoming, One-Way: Outgoing, Two-Way"
+           <> "'. Accepted values: one-way: incoming, one-way: outgoing, two-way"
 
 instance ToText TrustDirection where
     toText = \case
@@ -396,7 +396,7 @@ instance FromText TrustState where
         "verifyfailed" -> pure TSVerifyFailed
         "verifying" -> pure TSVerifying
         e -> fromTextError $ "Failure parsing TrustState from value: '" <> e
-           <> "'. Accepted values: Created, Creating, Deleted, Deleting, Failed, Verified, VerifyFailed, Verifying"
+           <> "'. Accepted values: created, creating, deleted, deleting, failed, verified, verifyfailed, verifying"
 
 instance ToText TrustState where
     toText = \case
@@ -426,7 +426,7 @@ instance FromText TrustType where
     parser = takeLowerText >>= \case
         "forest" -> pure Forest
         e -> fromTextError $ "Failure parsing TrustType from value: '" <> e
-           <> "'. Accepted values: Forest"
+           <> "'. Accepted values: forest"
 
 instance ToText TrustType where
     toText = \case
diff --git a/amazonka-dynamodb-streams/gen/Network/AWS/DynamoDBStreams/Types/Sum.hs b/amazonka-dynamodb-streams/gen/Network/AWS/DynamoDBStreams/Types/Sum.hs
index f6a0b8d0a77..4abfdb0054d 100644
--- a/amazonka-dynamodb-streams/gen/Network/AWS/DynamoDBStreams/Types/Sum.hs
+++ b/amazonka-dynamodb-streams/gen/Network/AWS/DynamoDBStreams/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText KeyType where
         "hash" -> pure Hash
         "range" -> pure Range
         e -> fromTextError $ "Failure parsing KeyType from value: '" <> e
-           <> "'. Accepted values: HASH, RANGE"
+           <> "'. Accepted values: hash, range"
 
 instance ToText KeyType where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText OperationType where
         "modify" -> pure Modify
         "remove" -> pure Remove
         e -> fromTextError $ "Failure parsing OperationType from value: '" <> e
-           <> "'. Accepted values: INSERT, MODIFY, REMOVE"
+           <> "'. Accepted values: insert, modify, remove"
 
 instance ToText OperationType where
     toText = \case
@@ -88,7 +88,7 @@ instance FromText ShardIteratorType where
         "latest" -> pure Latest
         "trim_horizon" -> pure TrimHorizon
         e -> fromTextError $ "Failure parsing ShardIteratorType from value: '" <> e
-           <> "'. Accepted values: AFTER_SEQUENCE_NUMBER, AT_SEQUENCE_NUMBER, LATEST, TRIM_HORIZON"
+           <> "'. Accepted values: after_sequence_number, at_sequence_number, latest, trim_horizon"
 
 instance ToText ShardIteratorType where
     toText = \case
@@ -120,7 +120,7 @@ instance FromText StreamStatus where
         "enabled" -> pure Enabled
         "enabling" -> pure Enabling
         e -> fromTextError $ "Failure parsing StreamStatus from value: '" <> e
-           <> "'. Accepted values: DISABLED, DISABLING, ENABLED, ENABLING"
+           <> "'. Accepted values: disabled, disabling, enabled, enabling"
 
 instance ToText StreamStatus where
     toText = \case
@@ -152,7 +152,7 @@ instance FromText StreamViewType where
         "new_image" -> pure NewImage
         "old_image" -> pure OldImage
         e -> fromTextError $ "Failure parsing StreamViewType from value: '" <> e
-           <> "'. Accepted values: KEYS_ONLY, NEW_AND_OLD_IMAGES, NEW_IMAGE, OLD_IMAGE"
+           <> "'. Accepted values: keys_only, new_and_old_images, new_image, old_image"
 
 instance ToText StreamViewType where
     toText = \case
diff --git a/amazonka-dynamodb/gen/Network/AWS/DynamoDB/Types/Sum.hs b/amazonka-dynamodb/gen/Network/AWS/DynamoDB/Types/Sum.hs
index 681e1b93e27..2cc2dbabecc 100644
--- a/amazonka-dynamodb/gen/Network/AWS/DynamoDB/Types/Sum.hs
+++ b/amazonka-dynamodb/gen/Network/AWS/DynamoDB/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText AttributeAction where
         "delete" -> pure Delete
         "put" -> pure Put
         e -> fromTextError $ "Failure parsing AttributeAction from value: '" <> e
-           <> "'. Accepted values: ADD, DELETE, PUT"
+           <> "'. Accepted values: add, delete, put"
 
 instance ToText AttributeAction where
     toText = \case
@@ -80,7 +80,7 @@ instance FromText ComparisonOperator where
         "not_null" -> pure NotNull
         "null" -> pure Null
         e -> fromTextError $ "Failure parsing ComparisonOperator from value: '" <> e
-           <> "'. Accepted values: BEGINS_WITH, BETWEEN, CONTAINS, EQ, GE, GT, IN, LE, LT, NE, NOT_CONTAINS, NOT_NULL, NULL"
+           <> "'. Accepted values: begins_with, between, contains, eq, ge, gt, in, le, lt, ne, not_contains, not_null, null"
 
 instance ToText ComparisonOperator where
     toText = \case
@@ -117,7 +117,7 @@ instance FromText ConditionalOperator where
         "and" -> pure And
         "or" -> pure OR
         e -> fromTextError $ "Failure parsing ConditionalOperator from value: '" <> e
-           <> "'. Accepted values: AND, OR"
+           <> "'. Accepted values: and, or"
 
 instance ToText ConditionalOperator where
     toText = \case
@@ -147,7 +147,7 @@ instance FromText IndexStatus where
         "deleting" -> pure ISDeleting
         "updating" -> pure ISUpdating
         e -> fromTextError $ "Failure parsing IndexStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, CREATING, DELETING, UPDATING"
+           <> "'. Accepted values: active, creating, deleting, updating"
 
 instance ToText IndexStatus where
     toText = \case
@@ -175,7 +175,7 @@ instance FromText KeyType where
         "hash" -> pure Hash
         "range" -> pure Range
         e -> fromTextError $ "Failure parsing KeyType from value: '" <> e
-           <> "'. Accepted values: HASH, RANGE"
+           <> "'. Accepted values: hash, range"
 
 instance ToText KeyType where
     toText = \case
@@ -206,7 +206,7 @@ instance FromText ProjectionType where
         "include" -> pure Include
         "keys_only" -> pure KeysOnly
         e -> fromTextError $ "Failure parsing ProjectionType from value: '" <> e
-           <> "'. Accepted values: ALL, INCLUDE, KEYS_ONLY"
+           <> "'. Accepted values: all, include, keys_only"
 
 instance ToText ProjectionType where
     toText = \case
@@ -248,7 +248,7 @@ instance FromText ReturnConsumedCapacity where
         "none" -> pure RCCNone
         "total" -> pure RCCTotal
         e -> fromTextError $ "Failure parsing ReturnConsumedCapacity from value: '" <> e
-           <> "'. Accepted values: INDEXES, NONE, TOTAL"
+           <> "'. Accepted values: indexes, none, total"
 
 instance ToText ReturnConsumedCapacity where
     toText = \case
@@ -275,7 +275,7 @@ instance FromText ReturnItemCollectionMetrics where
         "none" -> pure RICMNone
         "size" -> pure RICMSize
         e -> fromTextError $ "Failure parsing ReturnItemCollectionMetrics from value: '" <> e
-           <> "'. Accepted values: NONE, SIZE"
+           <> "'. Accepted values: none, size"
 
 instance ToText ReturnItemCollectionMetrics where
     toText = \case
@@ -307,7 +307,7 @@ instance FromText ReturnValue where
         "updated_new" -> pure UpdatedNew
         "updated_old" -> pure UpdatedOld
         e -> fromTextError $ "Failure parsing ReturnValue from value: '" <> e
-           <> "'. Accepted values: ALL_NEW, ALL_OLD, NONE, UPDATED_NEW, UPDATED_OLD"
+           <> "'. Accepted values: all_new, all_old, none, updated_new, updated_old"
 
 instance ToText ReturnValue where
     toText = \case
@@ -338,7 +338,7 @@ instance FromText ScalarAttributeType where
         "n" -> pure N
         "s" -> pure S
         e -> fromTextError $ "Failure parsing ScalarAttributeType from value: '" <> e
-           <> "'. Accepted values: B, N, S"
+           <> "'. Accepted values: b, n, s"
 
 instance ToText ScalarAttributeType where
     toText = \case
@@ -372,7 +372,7 @@ instance FromText Select where
         "count" -> pure Count
         "specific_attributes" -> pure SpecificAttributes
         e -> fromTextError $ "Failure parsing Select from value: '" <> e
-           <> "'. Accepted values: ALL_ATTRIBUTES, ALL_PROJECTED_ATTRIBUTES, COUNT, SPECIFIC_ATTRIBUTES"
+           <> "'. Accepted values: all_attributes, all_projected_attributes, count, specific_attributes"
 
 instance ToText Select where
     toText = \case
@@ -404,7 +404,7 @@ instance FromText StreamViewType where
         "new_image" -> pure SVTNewImage
         "old_image" -> pure SVTOldImage
         e -> fromTextError $ "Failure parsing StreamViewType from value: '" <> e
-           <> "'. Accepted values: KEYS_ONLY, NEW_AND_OLD_IMAGES, NEW_IMAGE, OLD_IMAGE"
+           <> "'. Accepted values: keys_only, new_and_old_images, new_image, old_image"
 
 instance ToText StreamViewType where
     toText = \case
@@ -439,7 +439,7 @@ instance FromText TableStatus where
         "deleting" -> pure Deleting
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing TableStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, CREATING, DELETING, UPDATING"
+           <> "'. Accepted values: active, creating, deleting, updating"
 
 instance ToText TableStatus where
     toText = \case
diff --git a/amazonka-ec2/gen/Network/AWS/EC2/Types/Sum.hs b/amazonka-ec2/gen/Network/AWS/EC2/Types/Sum.hs
index f5ac5553484..6ff65004a21 100644
--- a/amazonka-ec2/gen/Network/AWS/EC2/Types/Sum.hs
+++ b/amazonka-ec2/gen/Network/AWS/EC2/Types/Sum.hs
@@ -55,7 +55,7 @@ instance FromText AddressStatus where
         "invpc" -> pure InVPC
         "moveinprogress" -> pure MoveInProgress
         e -> fromTextError $ "Failure parsing AddressStatus from value: '" <> e
-           <> "'. Accepted values: InClassic, InVpc, MoveInProgress"
+           <> "'. Accepted values: inclassic, invpc, moveinprogress"
 
 instance ToText AddressStatus where
     toText = \case
@@ -140,7 +140,7 @@ instance FromText AllocationStrategy where
         "diversified" -> pure Diversified
         "lowestprice" -> pure LowestPrice
         e -> fromTextError $ "Failure parsing AllocationStrategy from value: '" <> e
-           <> "'. Accepted values: diversified, lowestPrice"
+           <> "'. Accepted values: diversified, lowestprice"
 
 instance ToText AllocationStrategy where
     toText = \case
@@ -374,7 +374,7 @@ instance FromText CancelBatchErrorCode where
         "fleetrequestnotincancellablestate" -> pure FleetRequestNotInCancellableState
         "unexpectederror" -> pure UnexpectedError
         e -> fromTextError $ "Failure parsing CancelBatchErrorCode from value: '" <> e
-           <> "'. Accepted values: fleetRequestIdDoesNotExist, fleetRequestIdMalformed, fleetRequestNotInCancellableState, unexpectedError"
+           <> "'. Accepted values: fleetrequestiddoesnotexist, fleetrequestidmalformed, fleetrequestnotincancellablestate, unexpectederror"
 
 instance ToText CancelBatchErrorCode where
     toText = \case
@@ -490,7 +490,7 @@ instance FromText CurrencyCodeValues where
     parser = takeLowerText >>= \case
         "usd" -> pure Usd
         e -> fromTextError $ "Failure parsing CurrencyCodeValues from value: '" <> e
-           <> "'. Accepted values: USD"
+           <> "'. Accepted values: usd"
 
 instance ToText CurrencyCodeValues where
     toText = \case
@@ -515,7 +515,7 @@ instance FromText DatafeedSubscriptionState where
         "active" -> pure DSSActive
         "inactive" -> pure DSSInactive
         e -> fromTextError $ "Failure parsing DatafeedSubscriptionState from value: '" <> e
-           <> "'. Accepted values: Active, Inactive"
+           <> "'. Accepted values: active, inactive"
 
 instance ToText DatafeedSubscriptionState where
     toText = \case
@@ -569,7 +569,7 @@ instance FromText DiskImageFormat where
         "vhd" -> pure VHD
         "vmdk" -> pure VMDK
         e -> fromTextError $ "Failure parsing DiskImageFormat from value: '" <> e
-           <> "'. Accepted values: RAW, VHD, VMDK"
+           <> "'. Accepted values: raw, vhd, vmdk"
 
 instance ToText DiskImageFormat where
     toText = \case
@@ -659,7 +659,7 @@ instance FromText EventType where
         "fleetrequestchange" -> pure FleetRequestChange
         "instancechange" -> pure InstanceChange
         e -> fromTextError $ "Failure parsing EventType from value: '" <> e
-           <> "'. Accepted values: error, fleetRequestChange, instanceChange"
+           <> "'. Accepted values: error, fleetrequestchange, instancechange"
 
 instance ToText EventType where
     toText = \case
@@ -686,7 +686,7 @@ instance FromText ExcessCapacityTerminationPolicy where
         "default" -> pure ECTPDefault
         "notermination" -> pure ECTPNoTermination
         e -> fromTextError $ "Failure parsing ExcessCapacityTerminationPolicy from value: '" <> e
-           <> "'. Accepted values: default, noTermination"
+           <> "'. Accepted values: default, notermination"
 
 instance ToText ExcessCapacityTerminationPolicy where
     toText = \case
@@ -801,7 +801,7 @@ instance FromText FlowLogsResourceType where
         "subnet" -> pure FLRTSubnet
         "vpc" -> pure FLRTVPC
         e -> fromTextError $ "Failure parsing FlowLogsResourceType from value: '" <> e
-           <> "'. Accepted values: NetworkInterface, Subnet, VPC"
+           <> "'. Accepted values: networkinterface, subnet, vpc"
 
 instance ToText FlowLogsResourceType where
     toText = \case
@@ -907,7 +907,7 @@ instance FromText ImageAttributeName where
         "ramdisk" -> pure RAMDisk
         "sriovnetsupport" -> pure SRIOVNetSupport
         e -> fromTextError $ "Failure parsing ImageAttributeName from value: '" <> e
-           <> "'. Accepted values: blockDeviceMapping, description, kernel, launchPermission, productCodes, ramdisk, sriovNetSupport"
+           <> "'. Accepted values: blockdevicemapping, description, kernel, launchpermission, productcodes, ramdisk, sriovnetsupport"
 
 instance ToText ImageAttributeName where
     toText = \case
@@ -1029,7 +1029,7 @@ instance FromText InstanceAttributeName where
         "sourcedestcheck" -> pure IANSourceDestCheck
         "userdata" -> pure IANUserData
         e -> fromTextError $ "Failure parsing InstanceAttributeName from value: '" <> e
-           <> "'. Accepted values: blockDeviceMapping, disableApiTermination, ebsOptimized, enaSupport, groupSet, instanceInitiatedShutdownBehavior, instanceType, kernel, productCodes, ramdisk, rootDeviceName, sriovNetSupport, sourceDestCheck, userData"
+           <> "'. Accepted values: blockdevicemapping, disableapitermination, ebsoptimized, enasupport, groupset, instanceinitiatedshutdownbehavior, instancetype, kernel, productcodes, ramdisk, rootdevicename, sriovnetsupport, sourcedestcheck, userdata"
 
 instance ToText InstanceAttributeName where
     toText = \case
@@ -1421,7 +1421,7 @@ instance FromText MoveStatus where
         "movingtovpc" -> pure MovingToVPC
         "restoringtoclassic" -> pure RestoringToClassic
         e -> fromTextError $ "Failure parsing MoveStatus from value: '" <> e
-           <> "'. Accepted values: movingToVpc, restoringToClassic"
+           <> "'. Accepted values: movingtovpc, restoringtoclassic"
 
 instance ToText MoveStatus where
     toText = \case
@@ -1486,7 +1486,7 @@ instance FromText NetworkInterfaceAttribute where
         "groupset" -> pure NIAGroupSet
         "sourcedestcheck" -> pure NIASourceDestCheck
         e -> fromTextError $ "Failure parsing NetworkInterfaceAttribute from value: '" <> e
-           <> "'. Accepted values: attachment, description, groupSet, sourceDestCheck"
+           <> "'. Accepted values: attachment, description, groupset, sourcedestcheck"
 
 instance ToText NetworkInterfaceAttribute where
     toText = \case
@@ -1543,7 +1543,7 @@ instance FromText NetworkInterfaceType where
         "interface" -> pure Interface
         "natgateway" -> pure NatGateway
         e -> fromTextError $ "Failure parsing NetworkInterfaceType from value: '" <> e
-           <> "'. Accepted values: interface, natGateway"
+           <> "'. Accepted values: interface, natgateway"
 
 instance ToText NetworkInterfaceType where
     toText = \case
@@ -1577,7 +1577,7 @@ instance FromText OfferingTypeValues where
         "no upfront" -> pure NoUpfront
         "partial upfront" -> pure PartialUpfront
         e -> fromTextError $ "Failure parsing OfferingTypeValues from value: '" <> e
-           <> "'. Accepted values: All Upfront, Heavy Utilization, Light Utilization, Medium Utilization, No Upfront, Partial Upfront"
+           <> "'. Accepted values: all upfront, heavy utilization, light utilization, medium utilization, no upfront, partial upfront"
 
 instance ToText OfferingTypeValues where
     toText = \case
@@ -1706,7 +1706,7 @@ instance FromText PlatformValues where
     parser = takeLowerText >>= \case
         "windows" -> pure Windows
         e -> fromTextError $ "Failure parsing PlatformValues from value: '" <> e
-           <> "'. Accepted values: Windows"
+           <> "'. Accepted values: windows"
 
 instance ToText PlatformValues where
     toText = \case
@@ -1761,7 +1761,7 @@ instance FromText RIProductDescription where
         "windows" -> pure RIDWindows
         "windows (amazon vpc)" -> pure RIDWindowsAmazonVPC
         e -> fromTextError $ "Failure parsing RIProductDescription from value: '" <> e
-           <> "'. Accepted values: Linux/UNIX, Linux/UNIX (Amazon VPC), Windows, Windows (Amazon VPC)"
+           <> "'. Accepted values: linux/unix, linux/unix (amazon vpc), windows, windows (amazon vpc)"
 
 instance ToText RIProductDescription where
     toText = \case
@@ -1787,7 +1787,7 @@ instance FromText RecurringChargeFrequency where
     parser = takeLowerText >>= \case
         "hourly" -> pure Hourly
         e -> fromTextError $ "Failure parsing RecurringChargeFrequency from value: '" <> e
-           <> "'. Accepted values: Hourly"
+           <> "'. Accepted values: hourly"
 
 instance ToText RecurringChargeFrequency where
     toText = \case
@@ -1909,7 +1909,7 @@ instance FromText ResetImageAttributeName where
     parser = takeLowerText >>= \case
         "launchpermission" -> pure RIANLaunchPermission
         e -> fromTextError $ "Failure parsing ResetImageAttributeName from value: '" <> e
-           <> "'. Accepted values: launchPermission"
+           <> "'. Accepted values: launchpermission"
 
 instance ToText ResetImageAttributeName where
     toText = \case
@@ -2004,7 +2004,7 @@ instance FromText RouteOrigin where
         "createroutetable" -> pure CreateRouteTable
         "enablevgwroutepropagation" -> pure EnableVGWRoutePropagation
         e -> fromTextError $ "Failure parsing RouteOrigin from value: '" <> e
-           <> "'. Accepted values: CreateRoute, CreateRouteTable, EnableVgwRoutePropagation"
+           <> "'. Accepted values: createroute, createroutetable, enablevgwroutepropagation"
 
 instance ToText RouteOrigin where
     toText = \case
@@ -2106,7 +2106,7 @@ instance FromText SnapshotAttributeName where
         "createvolumepermission" -> pure SANCreateVolumePermission
         "productcodes" -> pure SANProductCodes
         e -> fromTextError $ "Failure parsing SnapshotAttributeName from value: '" <> e
-           <> "'. Accepted values: createVolumePermission, productCodes"
+           <> "'. Accepted values: createvolumepermission, productcodes"
 
 instance ToText SnapshotAttributeName where
     toText = \case
@@ -2223,7 +2223,7 @@ instance FromText State where
         "deleting" -> pure SDeleting
         "pending" -> pure SPending
         e -> fromTextError $ "Failure parsing State from value: '" <> e
-           <> "'. Accepted values: Available, Deleted, Deleting, Pending"
+           <> "'. Accepted values: available, deleted, deleting, pending"
 
 instance ToText State where
     toText = \case
@@ -2367,7 +2367,7 @@ instance FromText TelemetryStatus where
         "down" -> pure Down
         "up" -> pure UP
         e -> fromTextError $ "Failure parsing TelemetryStatus from value: '" <> e
-           <> "'. Accepted values: DOWN, UP"
+           <> "'. Accepted values: down, up"
 
 instance ToText TelemetryStatus where
     toText = \case
@@ -2424,7 +2424,7 @@ instance FromText TrafficType where
         "all" -> pure TTAll
         "reject" -> pure TTReject
         e -> fromTextError $ "Failure parsing TrafficType from value: '" <> e
-           <> "'. Accepted values: ACCEPT, ALL, REJECT"
+           <> "'. Accepted values: accept, all, reject"
 
 instance ToText TrafficType where
     toText = \case
@@ -2451,7 +2451,7 @@ instance FromText VPCAttributeName where
         "enablednshostnames" -> pure EnableDNSHostnames
         "enablednssupport" -> pure EnableDNSSupport
         e -> fromTextError $ "Failure parsing VPCAttributeName from value: '" <> e
-           <> "'. Accepted values: enableDnsHostnames, enableDnsSupport"
+           <> "'. Accepted values: enablednshostnames, enablednssupport"
 
 instance ToText VPCAttributeName where
     toText = \case
@@ -2577,7 +2577,7 @@ instance FromText VPNStaticRouteSource where
     parser = takeLowerText >>= \case
         "static" -> pure Static
         e -> fromTextError $ "Failure parsing VPNStaticRouteSource from value: '" <> e
-           <> "'. Accepted values: Static"
+           <> "'. Accepted values: static"
 
 instance ToText VPNStaticRouteSource where
     toText = \case
@@ -2663,7 +2663,7 @@ instance FromText VolumeAttributeName where
         "autoenableio" -> pure VANAutoEnableIO
         "productcodes" -> pure VANProductCodes
         e -> fromTextError $ "Failure parsing VolumeAttributeName from value: '" <> e
-           <> "'. Accepted values: autoEnableIO, productCodes"
+           <> "'. Accepted values: autoenableio, productcodes"
 
 instance ToText VolumeAttributeName where
     toText = \case
diff --git a/amazonka-ecr/gen/Network/AWS/ECR/Types/Sum.hs b/amazonka-ecr/gen/Network/AWS/ECR/Types/Sum.hs
index 71d71494ee4..e613c37404a 100644
--- a/amazonka-ecr/gen/Network/AWS/ECR/Types/Sum.hs
+++ b/amazonka-ecr/gen/Network/AWS/ECR/Types/Sum.hs
@@ -35,7 +35,7 @@ instance FromText ImageFailureCode where
         "invalidimagetag" -> pure InvalidImageTag
         "missingdigestandtag" -> pure MissingDigestAndTag
         e -> fromTextError $ "Failure parsing ImageFailureCode from value: '" <> e
-           <> "'. Accepted values: ImageNotFound, ImageTagDoesNotMatchDigest, InvalidImageDigest, InvalidImageTag, MissingDigestAndTag"
+           <> "'. Accepted values: imagenotfound, imagetagdoesnotmatchdigest, invalidimagedigest, invalidimagetag, missingdigestandtag"
 
 instance ToText ImageFailureCode where
     toText = \case
@@ -64,7 +64,7 @@ instance FromText LayerAvailability where
         "available" -> pure Available
         "unavailable" -> pure Unavailable
         e -> fromTextError $ "Failure parsing LayerAvailability from value: '" <> e
-           <> "'. Accepted values: AVAILABLE, UNAVAILABLE"
+           <> "'. Accepted values: available, unavailable"
 
 instance ToText LayerAvailability where
     toText = \case
@@ -90,7 +90,7 @@ instance FromText LayerFailureCode where
         "invalidlayerdigest" -> pure InvalidLayerDigest
         "missinglayerdigest" -> pure MissingLayerDigest
         e -> fromTextError $ "Failure parsing LayerFailureCode from value: '" <> e
-           <> "'. Accepted values: InvalidLayerDigest, MissingLayerDigest"
+           <> "'. Accepted values: invalidlayerdigest, missinglayerdigest"
 
 instance ToText LayerFailureCode where
     toText = \case
@@ -116,7 +116,7 @@ instance FromText TagStatus where
         "tagged" -> pure Tagged
         "untagged" -> pure Untagged
         e -> fromTextError $ "Failure parsing TagStatus from value: '" <> e
-           <> "'. Accepted values: TAGGED, UNTAGGED"
+           <> "'. Accepted values: tagged, untagged"
 
 instance ToText TagStatus where
     toText = \case
diff --git a/amazonka-ecs/gen/Network/AWS/ECS/Types/Sum.hs b/amazonka-ecs/gen/Network/AWS/ECS/Types/Sum.hs
index 803cc10cdbf..7ebf8d42d4a 100644
--- a/amazonka-ecs/gen/Network/AWS/ECS/Types/Sum.hs
+++ b/amazonka-ecs/gen/Network/AWS/ECS/Types/Sum.hs
@@ -37,7 +37,7 @@ instance FromText AgentUpdateStatus where
         "updated" -> pure AUSUpdated
         "updating" -> pure AUSUpdating
         e -> fromTextError $ "Failure parsing AgentUpdateStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, PENDING, STAGED, STAGING, UPDATED, UPDATING"
+           <> "'. Accepted values: failed, pending, staged, staging, updated, updating"
 
 instance ToText AgentUpdateStatus where
     toText = \case
@@ -69,7 +69,7 @@ instance FromText DesiredStatus where
         "running" -> pure Running
         "stopped" -> pure Stopped
         e -> fromTextError $ "Failure parsing DesiredStatus from value: '" <> e
-           <> "'. Accepted values: PENDING, RUNNING, STOPPED"
+           <> "'. Accepted values: pending, running, stopped"
 
 instance ToText DesiredStatus where
     toText = \case
@@ -137,7 +137,7 @@ instance FromText SortOrder where
         "asc" -> pure Asc
         "desc" -> pure Desc
         e -> fromTextError $ "Failure parsing SortOrder from value: '" <> e
-           <> "'. Accepted values: ASC, DESC"
+           <> "'. Accepted values: asc, desc"
 
 instance ToText SortOrder where
     toText = \case
@@ -165,7 +165,7 @@ instance FromText TaskDefinitionFamilyStatus where
         "all" -> pure All
         "inactive" -> pure Inactive
         e -> fromTextError $ "Failure parsing TaskDefinitionFamilyStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, ALL, INACTIVE"
+           <> "'. Accepted values: active, all, inactive"
 
 instance ToText TaskDefinitionFamilyStatus where
     toText = \case
@@ -192,7 +192,7 @@ instance FromText TaskDefinitionStatus where
         "active" -> pure TDSActive
         "inactive" -> pure TDSInactive
         e -> fromTextError $ "Failure parsing TaskDefinitionStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, INACTIVE"
+           <> "'. Accepted values: active, inactive"
 
 instance ToText TaskDefinitionStatus where
     toText = \case
diff --git a/amazonka-efs/gen/Network/AWS/EFS/Types/Sum.hs b/amazonka-efs/gen/Network/AWS/EFS/Types/Sum.hs
index 2402f8a111c..2b91e071736 100644
--- a/amazonka-efs/gen/Network/AWS/EFS/Types/Sum.hs
+++ b/amazonka-efs/gen/Network/AWS/EFS/Types/Sum.hs
@@ -61,7 +61,7 @@ instance FromText PerformanceMode where
         "generalpurpose" -> pure GeneralPurpose
         "maxio" -> pure MaxIO
         e -> fromTextError $ "Failure parsing PerformanceMode from value: '" <> e
-           <> "'. Accepted values: generalPurpose, maxIO"
+           <> "'. Accepted values: generalpurpose, maxio"
 
 instance ToText PerformanceMode where
     toText = \case
diff --git a/amazonka-elasticbeanstalk/gen/Network/AWS/ElasticBeanstalk/Types/Sum.hs b/amazonka-elasticbeanstalk/gen/Network/AWS/ElasticBeanstalk/Types/Sum.hs
index cd27443919c..e005b2c7fab 100644
--- a/amazonka-elasticbeanstalk/gen/Network/AWS/ElasticBeanstalk/Types/Sum.hs
+++ b/amazonka-elasticbeanstalk/gen/Network/AWS/ElasticBeanstalk/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText ActionHistoryStatus where
         "failed" -> pure Failed
         "unknown" -> pure Unknown
         e -> fromTextError $ "Failure parsing ActionHistoryStatus from value: '" <> e
-           <> "'. Accepted values: Completed, Failed, Unknown"
+           <> "'. Accepted values: completed, failed, unknown"
 
 instance ToText ActionHistoryStatus where
     toText = \case
@@ -62,7 +62,7 @@ instance FromText ActionStatus where
         "scheduled" -> pure ASScheduled
         "unknown" -> pure ASUnknown
         e -> fromTextError $ "Failure parsing ActionStatus from value: '" <> e
-           <> "'. Accepted values: Pending, Running, Scheduled, Unknown"
+           <> "'. Accepted values: pending, running, scheduled, unknown"
 
 instance ToText ActionStatus where
     toText = \case
@@ -92,7 +92,7 @@ instance FromText ActionType where
         "platformupdate" -> pure ATPlatformUpdate
         "unknown" -> pure ATUnknown
         e -> fromTextError $ "Failure parsing ActionType from value: '" <> e
-           <> "'. Accepted values: InstanceRefresh, PlatformUpdate, Unknown"
+           <> "'. Accepted values: instancerefresh, platformupdate, unknown"
 
 instance ToText ActionType where
     toText = \case
@@ -123,7 +123,7 @@ instance FromText ApplicationVersionStatus where
         "processing" -> pure AVSProcessing
         "unprocessed" -> pure AVSUnprocessed
         e -> fromTextError $ "Failure parsing ApplicationVersionStatus from value: '" <> e
-           <> "'. Accepted values: Failed, Processed, Processing, Unprocessed"
+           <> "'. Accepted values: failed, processed, processing, unprocessed"
 
 instance ToText ApplicationVersionStatus where
     toText = \case
@@ -180,7 +180,7 @@ instance FromText ConfigurationOptionValueType where
         "list" -> pure List
         "scalar" -> pure Scalar
         e -> fromTextError $ "Failure parsing ConfigurationOptionValueType from value: '" <> e
-           <> "'. Accepted values: List, Scalar"
+           <> "'. Accepted values: list, scalar"
 
 instance ToText ConfigurationOptionValueType where
     toText = \case
@@ -210,7 +210,7 @@ instance FromText EnvironmentHealth where
         "red" -> pure Red
         "yellow" -> pure Yellow
         e -> fromTextError $ "Failure parsing EnvironmentHealth from value: '" <> e
-           <> "'. Accepted values: Green, Grey, Red, Yellow"
+           <> "'. Accepted values: green, grey, red, yellow"
 
 instance ToText EnvironmentHealth where
     toText = \case
@@ -250,7 +250,7 @@ instance FromText EnvironmentHealthAttribute where
         "refreshedat" -> pure EHARefreshedAt
         "status" -> pure EHAStatus
         e -> fromTextError $ "Failure parsing EnvironmentHealthAttribute from value: '" <> e
-           <> "'. Accepted values: All, ApplicationMetrics, Causes, Color, HealthStatus, InstancesHealth, RefreshedAt, Status"
+           <> "'. Accepted values: all, applicationmetrics, causes, color, healthstatus, instanceshealth, refreshedat, status"
 
 instance ToText EnvironmentHealthAttribute where
     toText = \case
@@ -291,7 +291,7 @@ instance FromText EnvironmentHealthStatus where
         "unknown" -> pure EHSUnknown
         "warning" -> pure EHSWarning
         e -> fromTextError $ "Failure parsing EnvironmentHealthStatus from value: '" <> e
-           <> "'. Accepted values: Degraded, Info, NoData, Ok, Pending, Severe, Unknown, Warning"
+           <> "'. Accepted values: degraded, info, nodata, ok, pending, severe, unknown, warning"
 
 instance ToText EnvironmentHealthStatus where
     toText = \case
@@ -355,7 +355,7 @@ instance FromText EnvironmentStatus where
         "terminating" -> pure Terminating
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing EnvironmentStatus from value: '" <> e
-           <> "'. Accepted values: Launching, Ready, Terminated, Terminating, Updating"
+           <> "'. Accepted values: launching, ready, terminated, terminating, updating"
 
 instance ToText EnvironmentStatus where
     toText = \case
@@ -392,7 +392,7 @@ instance FromText EventSeverity where
         "trace" -> pure LevelTrace
         "warn" -> pure LevelWarn
         e -> fromTextError $ "Failure parsing EventSeverity from value: '" <> e
-           <> "'. Accepted values: DEBUG, ERROR, FATAL, INFO, TRACE, WARN"
+           <> "'. Accepted values: debug, error, fatal, info, trace, warn"
 
 instance ToText EventSeverity where
     toText = \case
@@ -432,7 +432,7 @@ instance FromText FailureType where
         "rollbacksuccessful" -> pure RollbackSuccessful
         "updatecancelled" -> pure UpdateCancelled
         e -> fromTextError $ "Failure parsing FailureType from value: '" <> e
-           <> "'. Accepted values: CancellationFailed, InternalFailure, InvalidEnvironmentState, PermissionsError, RollbackFailed, RollbackSuccessful, UpdateCancelled"
+           <> "'. Accepted values: cancellationfailed, internalfailure, invalidenvironmentstate, permissionserror, rollbackfailed, rollbacksuccessful, updatecancelled"
 
 instance ToText FailureType where
     toText = \case
@@ -481,7 +481,7 @@ instance FromText InstancesHealthAttribute where
         "refreshedat" -> pure RefreshedAt
         "system" -> pure System
         e -> fromTextError $ "Failure parsing InstancesHealthAttribute from value: '" <> e
-           <> "'. Accepted values: All, ApplicationMetrics, AvailabilityZone, Causes, Color, Deployment, HealthStatus, InstanceType, LaunchedAt, RefreshedAt, System"
+           <> "'. Accepted values: all, applicationmetrics, availabilityzone, causes, color, deployment, healthstatus, instancetype, launchedat, refreshedat, system"
 
 instance ToText InstancesHealthAttribute where
     toText = \case
diff --git a/amazonka-elasticsearch/gen/Network/AWS/ElasticSearch/Types/Sum.hs b/amazonka-elasticsearch/gen/Network/AWS/ElasticSearch/Types/Sum.hs
index 883674f3d6d..b2c67ebf2e8 100644
--- a/amazonka-elasticsearch/gen/Network/AWS/ElasticSearch/Types/Sum.hs
+++ b/amazonka-elasticsearch/gen/Network/AWS/ElasticSearch/Types/Sum.hs
@@ -115,7 +115,7 @@ instance FromText OptionState where
         "processing" -> pure Processing
         "requiresindexdocuments" -> pure RequiresIndexDocuments
         e -> fromTextError $ "Failure parsing OptionState from value: '" <> e
-           <> "'. Accepted values: Active, Processing, RequiresIndexDocuments"
+           <> "'. Accepted values: active, processing, requiresindexdocuments"
 
 instance ToText OptionState where
     toText = \case
diff --git a/amazonka-elb-v2/gen/Network/AWS/ELBV2/Types/Sum.hs b/amazonka-elb-v2/gen/Network/AWS/ELBV2/Types/Sum.hs
index a9e74e9ced1..3d0de57d1d6 100644
--- a/amazonka-elb-v2/gen/Network/AWS/ELBV2/Types/Sum.hs
+++ b/amazonka-elb-v2/gen/Network/AWS/ELBV2/Types/Sum.hs
@@ -130,7 +130,7 @@ instance FromText ProtocolEnum where
         "http" -> pure HTTP
         "https" -> pure HTTPS
         e -> fromTextError $ "Failure parsing ProtocolEnum from value: '" <> e
-           <> "'. Accepted values: HTTP, HTTPS"
+           <> "'. Accepted values: http, https"
 
 instance ToText ProtocolEnum where
     toText = \case
@@ -172,7 +172,7 @@ instance FromText TargetHealthReasonEnum where
         "target.responsecodemismatch" -> pure Target_ResponseCodeMismatch
         "target.timeout" -> pure Target_Timeout
         e -> fromTextError $ "Failure parsing TargetHealthReasonEnum from value: '" <> e
-           <> "'. Accepted values: Elb.InitialHealthChecking, Elb.InternalError, Elb.RegistrationInProgress, Target.DeregistrationInProgress, Target.FailedHealthChecks, Target.InvalidState, Target.NotInUse, Target.NotRegistered, Target.ResponseCodeMismatch, Target.Timeout"
+           <> "'. Accepted values: elb.initialhealthchecking, elb.internalerror, elb.registrationinprogress, target.deregistrationinprogress, target.failedhealthchecks, target.invalidstate, target.notinuse, target.notregistered, target.responsecodemismatch, target.timeout"
 
 instance ToText TargetHealthReasonEnum where
     toText = \case
diff --git a/amazonka-emr/gen/Network/AWS/EMR/Types/Sum.hs b/amazonka-emr/gen/Network/AWS/EMR/Types/Sum.hs
index 9ab0d286b9f..6009b4b3364 100644
--- a/amazonka-emr/gen/Network/AWS/EMR/Types/Sum.hs
+++ b/amazonka-emr/gen/Network/AWS/EMR/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText ActionOnFailure where
         "terminate_cluster" -> pure TerminateCluster
         "terminate_job_flow" -> pure TerminateJobFlow
         e -> fromTextError $ "Failure parsing ActionOnFailure from value: '" <> e
-           <> "'. Accepted values: CANCEL_AND_WAIT, CONTINUE, TERMINATE_CLUSTER, TERMINATE_JOB_FLOW"
+           <> "'. Accepted values: cancel_and_wait, continue, terminate_cluster, terminate_job_flow"
 
 instance ToText ActionOnFailure where
     toText = \case
@@ -74,7 +74,7 @@ instance FromText ClusterState where
         "terminating" -> pure CSTerminating
         "waiting" -> pure CSWaiting
         e -> fromTextError $ "Failure parsing ClusterState from value: '" <> e
-           <> "'. Accepted values: BOOTSTRAPPING, RUNNING, STARTING, TERMINATED, TERMINATED_WITH_ERRORS, TERMINATING, WAITING"
+           <> "'. Accepted values: bootstrapping, running, starting, terminated, terminated_with_errors, terminating, waiting"
 
 instance ToText ClusterState where
     toText = \case
@@ -118,7 +118,7 @@ instance FromText ClusterStateChangeReasonCode where
         "user_request" -> pure CSCRCUserRequest
         "validation_error" -> pure CSCRCValidationError
         e -> fromTextError $ "Failure parsing ClusterStateChangeReasonCode from value: '" <> e
-           <> "'. Accepted values: ALL_STEPS_COMPLETED, BOOTSTRAP_FAILURE, INSTANCE_FAILURE, INTERNAL_ERROR, STEP_FAILURE, USER_REQUEST, VALIDATION_ERROR"
+           <> "'. Accepted values: all_steps_completed, bootstrap_failure, instance_failure, internal_error, step_failure, user_request, validation_error"
 
 instance ToText ClusterStateChangeReasonCode where
     toText = \case
@@ -165,7 +165,7 @@ instance FromText InstanceGroupState where
         "terminated" -> pure Terminated
         "terminating" -> pure Terminating
         e -> fromTextError $ "Failure parsing InstanceGroupState from value: '" <> e
-           <> "'. Accepted values: ARRESTED, BOOTSTRAPPING, ENDED, PROVISIONING, RESIZING, RUNNING, SHUTTING_DOWN, SUSPENDED, TERMINATED, TERMINATING"
+           <> "'. Accepted values: arrested, bootstrapping, ended, provisioning, resizing, running, shutting_down, suspended, terminated, terminating"
 
 instance ToText InstanceGroupState where
     toText = \case
@@ -203,7 +203,7 @@ instance FromText InstanceGroupStateChangeReasonCode where
         "internal_error" -> pure InternalError
         "validation_error" -> pure ValidationError
         e -> fromTextError $ "Failure parsing InstanceGroupStateChangeReasonCode from value: '" <> e
-           <> "'. Accepted values: CLUSTER_TERMINATED, INSTANCE_FAILURE, INTERNAL_ERROR, VALIDATION_ERROR"
+           <> "'. Accepted values: cluster_terminated, instance_failure, internal_error, validation_error"
 
 instance ToText InstanceGroupStateChangeReasonCode where
     toText = \case
@@ -233,7 +233,7 @@ instance FromText InstanceGroupType where
         "master" -> pure Master
         "task" -> pure Task
         e -> fromTextError $ "Failure parsing InstanceGroupType from value: '" <> e
-           <> "'. Accepted values: CORE, MASTER, TASK"
+           <> "'. Accepted values: core, master, task"
 
 instance ToText InstanceGroupType where
     toText = \case
@@ -265,7 +265,7 @@ instance FromText InstanceRoleType where
         "master" -> pure IRTMaster
         "task" -> pure IRTTask
         e -> fromTextError $ "Failure parsing InstanceRoleType from value: '" <> e
-           <> "'. Accepted values: CORE, MASTER, TASK"
+           <> "'. Accepted values: core, master, task"
 
 instance ToText InstanceRoleType where
     toText = \case
@@ -298,7 +298,7 @@ instance FromText InstanceState where
         "running" -> pure ISRunning
         "terminated" -> pure ISTerminated
         e -> fromTextError $ "Failure parsing InstanceState from value: '" <> e
-           <> "'. Accepted values: AWAITING_FULFILLMENT, BOOTSTRAPPING, PROVISIONING, RUNNING, TERMINATED"
+           <> "'. Accepted values: awaiting_fulfillment, bootstrapping, provisioning, running, terminated"
 
 instance ToText InstanceState where
     toText = \case
@@ -336,7 +336,7 @@ instance FromText InstanceStateChangeReasonCode where
         "internal_error" -> pure ISCRCInternalError
         "validation_error" -> pure ISCRCValidationError
         e -> fromTextError $ "Failure parsing InstanceStateChangeReasonCode from value: '" <> e
-           <> "'. Accepted values: BOOTSTRAP_FAILURE, CLUSTER_TERMINATED, INSTANCE_FAILURE, INTERNAL_ERROR, VALIDATION_ERROR"
+           <> "'. Accepted values: bootstrap_failure, cluster_terminated, instance_failure, internal_error, validation_error"
 
 instance ToText InstanceStateChangeReasonCode where
     toText = \case
@@ -365,7 +365,7 @@ instance FromText MarketType where
         "on_demand" -> pure OnDemand
         "spot" -> pure Spot
         e -> fromTextError $ "Failure parsing MarketType from value: '" <> e
-           <> "'. Accepted values: ON_DEMAND, SPOT"
+           <> "'. Accepted values: on_demand, spot"
 
 instance ToText MarketType where
     toText = \case
@@ -402,7 +402,7 @@ instance FromText StepState where
         "pending" -> pure SSPending
         "running" -> pure SSRunning
         e -> fromTextError $ "Failure parsing StepState from value: '" <> e
-           <> "'. Accepted values: CANCELLED, COMPLETED, FAILED, INTERRUPTED, PENDING, RUNNING"
+           <> "'. Accepted values: cancelled, completed, failed, interrupted, pending, running"
 
 instance ToText StepState where
     toText = \case
@@ -433,7 +433,7 @@ instance FromText StepStateChangeReasonCode where
     parser = takeLowerText >>= \case
         "none" -> pure None
         e -> fromTextError $ "Failure parsing StepStateChangeReasonCode from value: '" <> e
-           <> "'. Accepted values: NONE"
+           <> "'. Accepted values: none"
 
 instance ToText StepStateChangeReasonCode where
     toText = \case
diff --git a/amazonka-gamelift/gen/Network/AWS/GameLift/Types/Sum.hs b/amazonka-gamelift/gen/Network/AWS/GameLift/Types/Sum.hs
index 606afeddd7f..8d62acff149 100644
--- a/amazonka-gamelift/gen/Network/AWS/GameLift/Types/Sum.hs
+++ b/amazonka-gamelift/gen/Network/AWS/GameLift/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText BuildStatus where
         "initialized" -> pure Initialized
         "ready" -> pure Ready
         e -> fromTextError $ "Failure parsing BuildStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, INITIALIZED, READY"
+           <> "'. Accepted values: failed, initialized, ready"
 
 instance ToText BuildStatus where
     toText = \case
@@ -65,7 +65,7 @@ instance FromText ComparisonOperatorType where
         "lessthanorequaltothreshold" -> pure LessThanOrEqualToThreshold
         "lessthanthreshold" -> pure LessThanThreshold
         e -> fromTextError $ "Failure parsing ComparisonOperatorType from value: '" <> e
-           <> "'. Accepted values: GreaterThanOrEqualToThreshold, GreaterThanThreshold, LessThanOrEqualToThreshold, LessThanThreshold"
+           <> "'. Accepted values: greaterthanorequaltothreshold, greaterthanthreshold, lessthanorequaltothreshold, lessthanthreshold"
 
 instance ToText ComparisonOperatorType where
     toText = \case
@@ -235,7 +235,7 @@ instance FromText EventCode where
         "fleet_validation_timed_out" -> pure FleetValidationTimedOut
         "generic_event" -> pure GenericEvent
         e -> fromTextError $ "Failure parsing EventCode from value: '" <> e
-           <> "'. Accepted values: FLEET_ACTIVATION_FAILED, FLEET_ACTIVATION_FAILED_NO_INSTANCES, FLEET_BINARY_DOWNLOAD_FAILED, FLEET_CREATED, FLEET_DELETED, FLEET_INITIALIZATION_FAILED, FLEET_NEW_GAME_SESSION_PROTECTION_POLICY_UPDATED, FLEET_SCALING_EVENT, FLEET_STATE_ACTIVATING, FLEET_STATE_ACTIVE, FLEET_STATE_BUILDING, FLEET_STATE_DOWNLOADING, FLEET_STATE_ERROR, FLEET_STATE_VALIDATING, FLEET_VALIDATION_EXECUTABLE_RUNTIME_FAILURE, FLEET_VALIDATION_LAUNCH_PATH_NOT_FOUND, FLEET_VALIDATION_TIMED_OUT, GENERIC_EVENT"
+           <> "'. Accepted values: fleet_activation_failed, fleet_activation_failed_no_instances, fleet_binary_download_failed, fleet_created, fleet_deleted, fleet_initialization_failed, fleet_new_game_session_protection_policy_updated, fleet_scaling_event, fleet_state_activating, fleet_state_active, fleet_state_building, fleet_state_downloading, fleet_state_error, fleet_state_validating, fleet_validation_executable_runtime_failure, fleet_validation_launch_path_not_found, fleet_validation_timed_out, generic_event"
 
 instance ToText EventCode where
     toText = \case
@@ -291,7 +291,7 @@ instance FromText FleetStatus where
         "terminated" -> pure FSTerminated
         "validating" -> pure FSValidating
         e -> fromTextError $ "Failure parsing FleetStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVATING, ACTIVE, BUILDING, DELETING, DOWNLOADING, ERROR, NEW, TERMINATED, VALIDATING"
+           <> "'. Accepted values: activating, active, building, deleting, downloading, error, new, terminated, validating"
 
 instance ToText FleetStatus where
     toText = \case
@@ -328,7 +328,7 @@ instance FromText GameSessionStatus where
         "terminated" -> pure GSSTerminated
         "terminating" -> pure GSSTerminating
         e -> fromTextError $ "Failure parsing GameSessionStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVATING, ACTIVE, TERMINATED, TERMINATING"
+           <> "'. Accepted values: activating, active, terminated, terminating"
 
 instance ToText GameSessionStatus where
     toText = \case
@@ -356,7 +356,7 @@ instance FromText IPProtocol where
         "tcp" -> pure TCP
         "udp" -> pure Udp
         e -> fromTextError $ "Failure parsing IPProtocol from value: '" <> e
-           <> "'. Accepted values: TCP, UDP"
+           <> "'. Accepted values: tcp, udp"
 
 instance ToText IPProtocol where
     toText = \case
@@ -393,7 +393,7 @@ instance FromText MetricName where
         "currentplayersessions" -> pure CurrentPlayerSessions
         "idleinstances" -> pure IdleInstances
         e -> fromTextError $ "Failure parsing MetricName from value: '" <> e
-           <> "'. Accepted values: ActivatingGameSessions, ActiveGameSessions, ActiveInstances, AvailablePlayerSessions, CurrentPlayerSessions, IdleInstances"
+           <> "'. Accepted values: activatinggamesessions, activegamesessions, activeinstances, availableplayersessions, currentplayersessions, idleinstances"
 
 instance ToText MetricName where
     toText = \case
@@ -426,7 +426,7 @@ instance FromText PlayerSessionCreationPolicy where
         "accept_all" -> pure AcceptAll
         "deny_all" -> pure DenyAll
         e -> fromTextError $ "Failure parsing PlayerSessionCreationPolicy from value: '" <> e
-           <> "'. Accepted values: ACCEPT_ALL, DENY_ALL"
+           <> "'. Accepted values: accept_all, deny_all"
 
 instance ToText PlayerSessionCreationPolicy where
     toText = \case
@@ -459,7 +459,7 @@ instance FromText PlayerSessionStatus where
         "reserved" -> pure PSSReserved
         "timedout" -> pure PSSTimedout
         e -> fromTextError $ "Failure parsing PlayerSessionStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, COMPLETED, RESERVED, TIMEDOUT"
+           <> "'. Accepted values: active, completed, reserved, timedout"
 
 instance ToText PlayerSessionStatus where
     toText = \case
@@ -487,7 +487,7 @@ instance FromText ProtectionPolicy where
         "fullprotection" -> pure FullProtection
         "noprotection" -> pure NoProtection
         e -> fromTextError $ "Failure parsing ProtectionPolicy from value: '" <> e
-           <> "'. Accepted values: FullProtection, NoProtection"
+           <> "'. Accepted values: fullprotection, noprotection"
 
 instance ToText ProtectionPolicy where
     toText = \case
@@ -516,7 +516,7 @@ instance FromText RoutingStrategyType where
         "simple" -> pure Simple
         "terminal" -> pure Terminal
         e -> fromTextError $ "Failure parsing RoutingStrategyType from value: '" <> e
-           <> "'. Accepted values: SIMPLE, TERMINAL"
+           <> "'. Accepted values: simple, terminal"
 
 instance ToText RoutingStrategyType where
     toText = \case
@@ -547,7 +547,7 @@ instance FromText ScalingAdjustmentType where
         "exactcapacity" -> pure ExactCapacity
         "percentchangeincapacity" -> pure PercentChangeInCapacity
         e -> fromTextError $ "Failure parsing ScalingAdjustmentType from value: '" <> e
-           <> "'. Accepted values: ChangeInCapacity, ExactCapacity, PercentChangeInCapacity"
+           <> "'. Accepted values: changeincapacity, exactcapacity, percentchangeincapacity"
 
 instance ToText ScalingAdjustmentType where
     toText = \case
@@ -587,7 +587,7 @@ instance FromText ScalingStatusType where
         "update_requested" -> pure UpdateRequested
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing ScalingStatusType from value: '" <> e
-           <> "'. Accepted values: ACTIVE, DELETE_REQUESTED, DELETED, DELETING, ERROR, UPDATE_REQUESTED, UPDATING"
+           <> "'. Accepted values: active, delete_requested, deleted, deleting, error, update_requested, updating"
 
 instance ToText ScalingStatusType where
     toText = \case
diff --git a/amazonka-glacier/gen/Network/AWS/Glacier/Types/Sum.hs b/amazonka-glacier/gen/Network/AWS/Glacier/Types/Sum.hs
index 933f299da91..f002592e5c8 100644
--- a/amazonka-glacier/gen/Network/AWS/Glacier/Types/Sum.hs
+++ b/amazonka-glacier/gen/Network/AWS/Glacier/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText ActionCode where
         "archiveretrieval" -> pure ArchiveRetrieval
         "inventoryretrieval" -> pure InventoryRetrieval
         e -> fromTextError $ "Failure parsing ActionCode from value: '" <> e
-           <> "'. Accepted values: ArchiveRetrieval, InventoryRetrieval"
+           <> "'. Accepted values: archiveretrieval, inventoryretrieval"
 
 instance ToText ActionCode where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText StatusCode where
         "inprogress" -> pure InProgress
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing StatusCode from value: '" <> e
-           <> "'. Accepted values: Failed, InProgress, Succeeded"
+           <> "'. Accepted values: failed, inprogress, succeeded"
 
 instance ToText StatusCode where
     toText = \case
diff --git a/amazonka-iam/gen/Network/AWS/IAM/Types/Sum.hs b/amazonka-iam/gen/Network/AWS/IAM/Types/Sum.hs
index 0fe20b9f6aa..a95ac197ba4 100644
--- a/amazonka-iam/gen/Network/AWS/IAM/Types/Sum.hs
+++ b/amazonka-iam/gen/Network/AWS/IAM/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText AssignmentStatusType where
         "assigned" -> pure Assigned
         "unassigned" -> pure Unassigned
         e -> fromTextError $ "Failure parsing AssignmentStatusType from value: '" <> e
-           <> "'. Accepted values: Any, Assigned, Unassigned"
+           <> "'. Accepted values: any, assigned, unassigned"
 
 instance ToText AssignmentStatusType where
     toText = \case
@@ -75,7 +75,7 @@ instance FromText ContextKeyTypeEnum where
         "string" -> pure String
         "stringlist" -> pure StringList
         e -> fromTextError $ "Failure parsing ContextKeyTypeEnum from value: '" <> e
-           <> "'. Accepted values: binary, binaryList, boolean, booleanList, date, dateList, ip, ipList, numeric, numericList, string, stringList"
+           <> "'. Accepted values: binary, binarylist, boolean, booleanlist, date, datelist, ip, iplist, numeric, numericlist, string, stringlist"
 
 instance ToText ContextKeyTypeEnum where
     toText = \case
@@ -108,7 +108,7 @@ instance FromText EncodingType where
         "pem" -> pure Pem
         "ssh" -> pure SSH
         e -> fromTextError $ "Failure parsing EncodingType from value: '" <> e
-           <> "'. Accepted values: PEM, SSH"
+           <> "'. Accepted values: pem, ssh"
 
 instance ToText EncodingType where
     toText = \case
@@ -137,7 +137,7 @@ instance FromText EntityType where
         "role" -> pure ETRole
         "user" -> pure ETUser
         e -> fromTextError $ "Failure parsing EntityType from value: '" <> e
-           <> "'. Accepted values: AWSManagedPolicy, Group, LocalManagedPolicy, Role, User"
+           <> "'. Accepted values: awsmanagedpolicy, group, localmanagedpolicy, role, user"
 
 instance ToText EntityType where
     toText = \case
@@ -165,7 +165,7 @@ instance FromText PolicyEvaluationDecisionType where
         "explicitdeny" -> pure ExplicitDeny
         "implicitdeny" -> pure ImplicitDeny
         e -> fromTextError $ "Failure parsing PolicyEvaluationDecisionType from value: '" <> e
-           <> "'. Accepted values: allowed, explicitDeny, implicitDeny"
+           <> "'. Accepted values: allowed, explicitdeny, implicitdeny"
 
 instance ToText PolicyEvaluationDecisionType where
     toText = \case
@@ -194,7 +194,7 @@ instance FromText PolicyScopeType where
         "all" -> pure All
         "local" -> pure Local
         e -> fromTextError $ "Failure parsing PolicyScopeType from value: '" <> e
-           <> "'. Accepted values: AWS, All, Local"
+           <> "'. Accepted values: aws, all, local"
 
 instance ToText PolicyScopeType where
     toText = \case
@@ -284,7 +284,7 @@ instance FromText ReportStateType where
         "inprogress" -> pure Inprogress
         "started" -> pure Started
         e -> fromTextError $ "Failure parsing ReportStateType from value: '" <> e
-           <> "'. Accepted values: COMPLETE, INPROGRESS, STARTED"
+           <> "'. Accepted values: complete, inprogress, started"
 
 instance ToText ReportStateType where
     toText = \case
@@ -311,7 +311,7 @@ instance FromText StatusType where
         "active" -> pure Active
         "inactive" -> pure Inactive
         e -> fromTextError $ "Failure parsing StatusType from value: '" <> e
-           <> "'. Accepted values: Active, Inactive"
+           <> "'. Accepted values: active, inactive"
 
 instance ToText StatusType where
     toText = \case
@@ -383,7 +383,7 @@ instance FromText SummaryKeyType where
         "usersquota" -> pure UsersQuota
         "versionsperpolicyquota" -> pure VersionsPerPolicyQuota
         e -> fromTextError $ "Failure parsing SummaryKeyType from value: '" <> e
-           <> "'. Accepted values: AccessKeysPerUserQuota, AccountAccessKeysPresent, AccountMFAEnabled, AccountSigningCertificatesPresent, AttachedPoliciesPerGroupQuota, AttachedPoliciesPerRoleQuota, AttachedPoliciesPerUserQuota, GroupPolicySizeQuota, Groups, GroupsPerUserQuota, GroupsQuota, MFADevices, MFADevicesInUse, Policies, PoliciesQuota, PolicySizeQuota, PolicyVersionsInUse, PolicyVersionsInUseQuota, ServerCertificates, ServerCertificatesQuota, SigningCertificatesPerUserQuota, UserPolicySizeQuota, Users, UsersQuota, VersionsPerPolicyQuota"
+           <> "'. Accepted values: accesskeysperuserquota, accountaccesskeyspresent, accountmfaenabled, accountsigningcertificatespresent, attachedpoliciespergroupquota, attachedpoliciesperrolequota, attachedpoliciesperuserquota, grouppolicysizequota, groups, groupsperuserquota, groupsquota, mfadevices, mfadevicesinuse, policies, policiesquota, policysizequota, policyversionsinuse, policyversionsinusequota, servercertificates, servercertificatesquota, signingcertificatesperuserquota, userpolicysizequota, users, usersquota, versionsperpolicyquota"
 
 instance ToText SummaryKeyType where
     toText = \case
diff --git a/amazonka-importexport/gen/Network/AWS/ImportExport/Types/Sum.hs b/amazonka-importexport/gen/Network/AWS/ImportExport/Types/Sum.hs
index 2458e1d0bf4..e1d4eef168b 100644
--- a/amazonka-importexport/gen/Network/AWS/ImportExport/Types/Sum.hs
+++ b/amazonka-importexport/gen/Network/AWS/ImportExport/Types/Sum.hs
@@ -30,7 +30,7 @@ instance FromText JobType where
         "export" -> pure Export
         "import" -> pure Import
         e -> fromTextError $ "Failure parsing JobType from value: '" <> e
-           <> "'. Accepted values: Export, Import"
+           <> "'. Accepted values: export, import"
 
 instance ToText JobType where
     toText = \case
diff --git a/amazonka-inspector/gen/Network/AWS/Inspector/Types/Sum.hs b/amazonka-inspector/gen/Network/AWS/Inspector/Types/Sum.hs
index 1bb44bd3d25..e270baf44f1 100644
--- a/amazonka-inspector/gen/Network/AWS/Inspector/Types/Sum.hs
+++ b/amazonka-inspector/gen/Network/AWS/Inspector/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText AgentHealth where
         "healthy" -> pure AHHealthy
         "unhealthy" -> pure AHUnhealthy
         e -> fromTextError $ "Failure parsing AgentHealth from value: '" <> e
-           <> "'. Accepted values: HEALTHY, UNHEALTHY"
+           <> "'. Accepted values: healthy, unhealthy"
 
 instance ToText AgentHealth where
     toText = \case
@@ -66,7 +66,7 @@ instance FromText AgentHealthCode where
         "unhealthy" -> pure Unhealthy
         "unknown" -> pure Unknown
         e -> fromTextError $ "Failure parsing AgentHealthCode from value: '" <> e
-           <> "'. Accepted values: IDLE, RUNNING, SHUTDOWN, THROTTLED, UNHEALTHY, UNKNOWN"
+           <> "'. Accepted values: idle, running, shutdown, throttled, unhealthy, unknown"
 
 instance ToText AgentHealthCode where
     toText = \case
@@ -103,7 +103,7 @@ instance FromText AssessmentRunNotificationSNSStatusCode where
         "success" -> pure Success
         "topic_does_not_exist" -> pure TopicDoesNotExist
         e -> fromTextError $ "Failure parsing AssessmentRunNotificationSNSStatusCode from value: '" <> e
-           <> "'. Accepted values: ACCESS_DENIED, INTERNAL_ERROR, SUCCESS, TOPIC_DOES_NOT_EXIST"
+           <> "'. Accepted values: access_denied, internal_error, success, topic_does_not_exist"
 
 instance ToText AssessmentRunNotificationSNSStatusCode where
     toText = \case
@@ -147,7 +147,7 @@ instance FromText AssessmentRunState where
         "start_data_collection_pending" -> pure StartDataCollectionPending
         "stop_data_collection_pending" -> pure StopDataCollectionPending
         e -> fromTextError $ "Failure parsing AssessmentRunState from value: '" <> e
-           <> "'. Accepted values: COLLECTING_DATA, COMPLETED, COMPLETED_WITH_ERRORS, CREATED, DATA_COLLECTED, EVALUATING_RULES, FAILED, START_DATA_COLLECTION_IN_PROGRESS, START_DATA_COLLECTION_PENDING, STOP_DATA_COLLECTION_PENDING"
+           <> "'. Accepted values: collecting_data, completed, completed_with_errors, created, data_collected, evaluating_rules, failed, start_data_collection_in_progress, start_data_collection_pending, stop_data_collection_pending"
 
 instance ToText AssessmentRunState where
     toText = \case
@@ -215,7 +215,7 @@ instance FromText FailedItemErrorCode where
         "item_does_not_exist" -> pure FIECItemDoesNotExist
         "limit_exceeded" -> pure FIECLimitExceeded
         e -> fromTextError $ "Failure parsing FailedItemErrorCode from value: '" <> e
-           <> "'. Accepted values: ACCESS_DENIED, DUPLICATE_ARN, INTERNAL_ERROR, INVALID_ARN, ITEM_DOES_NOT_EXIST, LIMIT_EXCEEDED"
+           <> "'. Accepted values: access_denied, duplicate_arn, internal_error, invalid_arn, item_does_not_exist, limit_exceeded"
 
 instance ToText FailedItemErrorCode where
     toText = \case
@@ -251,7 +251,7 @@ instance FromText InspectorEvent where
         "finding_reported" -> pure FindingReported
         "other" -> pure Other
         e -> fromTextError $ "Failure parsing InspectorEvent from value: '" <> e
-           <> "'. Accepted values: ASSESSMENT_RUN_COMPLETED, ASSESSMENT_RUN_STARTED, ASSESSMENT_RUN_STATE_CHANGED, FINDING_REPORTED, OTHER"
+           <> "'. Accepted values: assessment_run_completed, assessment_run_started, assessment_run_state_changed, finding_reported, other"
 
 instance ToText InspectorEvent where
     toText = \case
@@ -281,7 +281,7 @@ instance FromText Locale where
     parser = takeLowerText >>= \case
         "en_us" -> pure EnUs
         e -> fromTextError $ "Failure parsing Locale from value: '" <> e
-           <> "'. Accepted values: EN_US"
+           <> "'. Accepted values: en_us"
 
 instance ToText Locale where
     toText = \case
@@ -312,7 +312,7 @@ instance FromText Severity where
         "medium" -> pure Medium
         "undefined" -> pure Undefined
         e -> fromTextError $ "Failure parsing Severity from value: '" <> e
-           <> "'. Accepted values: High, Informational, Low, Medium, Undefined"
+           <> "'. Accepted values: high, informational, low, medium, undefined"
 
 instance ToText Severity where
     toText = \case
diff --git a/amazonka-iot/gen/Network/AWS/IoT/Types/Sum.hs b/amazonka-iot/gen/Network/AWS/IoT/Types/Sum.hs
index 8d3acef45e1..47840fa6ce5 100644
--- a/amazonka-iot/gen/Network/AWS/IoT/Types/Sum.hs
+++ b/amazonka-iot/gen/Network/AWS/IoT/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText AutoRegistrationStatus where
         "disable" -> pure Disable
         "enable" -> pure Enable
         e -> fromTextError $ "Failure parsing AutoRegistrationStatus from value: '" <> e
-           <> "'. Accepted values: DISABLE, ENABLE"
+           <> "'. Accepted values: disable, enable"
 
 instance ToText AutoRegistrationStatus where
     toText = \case
@@ -58,7 +58,7 @@ instance FromText CACertificateStatus where
         "active" -> pure CACSActive
         "inactive" -> pure CACSInactive
         e -> fromTextError $ "Failure parsing CACertificateStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, INACTIVE"
+           <> "'. Accepted values: active, inactive"
 
 instance ToText CACertificateStatus where
     toText = \case
@@ -95,7 +95,7 @@ instance FromText CertificateStatus where
         "register_inactive" -> pure RegisterInactive
         "revoked" -> pure Revoked
         e -> fromTextError $ "Failure parsing CertificateStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, INACTIVE, PENDING_ACTIVATION, PENDING_TRANSFER, REGISTER_INACTIVE, REVOKED"
+           <> "'. Accepted values: active, inactive, pending_activation, pending_transfer, register_inactive, revoked"
 
 instance ToText CertificateStatus where
     toText = \case
@@ -128,7 +128,7 @@ instance FromText DynamoKeyType where
         "number" -> pure Number
         "string" -> pure String
         e -> fromTextError $ "Failure parsing DynamoKeyType from value: '" <> e
-           <> "'. Accepted values: NUMBER, STRING"
+           <> "'. Accepted values: number, string"
 
 instance ToText DynamoKeyType where
     toText = \case
@@ -163,7 +163,7 @@ instance FromText LogLevel where
         "info" -> pure Info
         "warn" -> pure Warn
         e -> fromTextError $ "Failure parsing LogLevel from value: '" <> e
-           <> "'. Accepted values: DEBUG, DISABLED, ERROR, INFO, WARN"
+           <> "'. Accepted values: debug, disabled, error, info, warn"
 
 instance ToText LogLevel where
     toText = \case
@@ -195,7 +195,7 @@ instance FromText MessageFormat where
         "json" -> pure JSON
         "raw" -> pure Raw
         e -> fromTextError $ "Failure parsing MessageFormat from value: '" <> e
-           <> "'. Accepted values: JSON, RAW"
+           <> "'. Accepted values: json, raw"
 
 instance ToText MessageFormat where
     toText = \case
diff --git a/amazonka-kinesis-analytics/gen/Network/AWS/KinesisAnalytics/Types/Sum.hs b/amazonka-kinesis-analytics/gen/Network/AWS/KinesisAnalytics/Types/Sum.hs
index 0bb3c3d6d0a..143a8ba4d7a 100644
--- a/amazonka-kinesis-analytics/gen/Network/AWS/KinesisAnalytics/Types/Sum.hs
+++ b/amazonka-kinesis-analytics/gen/Network/AWS/KinesisAnalytics/Types/Sum.hs
@@ -37,7 +37,7 @@ instance FromText ApplicationStatus where
         "stopping" -> pure Stopping
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing ApplicationStatus from value: '" <> e
-           <> "'. Accepted values: DELETING, READY, RUNNING, STARTING, STOPPING, UPDATING"
+           <> "'. Accepted values: deleting, ready, running, starting, stopping, updating"
 
 instance ToText ApplicationStatus where
     toText = \case
@@ -69,7 +69,7 @@ instance FromText InputStartingPosition where
         "now" -> pure Now
         "trim_horizon" -> pure TrimHorizon
         e -> fromTextError $ "Failure parsing InputStartingPosition from value: '" <> e
-           <> "'. Accepted values: LAST_STOPPED_POINT, NOW, TRIM_HORIZON"
+           <> "'. Accepted values: last_stopped_point, now, trim_horizon"
 
 instance ToText InputStartingPosition where
     toText = \case
@@ -99,7 +99,7 @@ instance FromText RecordFormatType where
         "csv" -> pure CSV
         "json" -> pure JSON
         e -> fromTextError $ "Failure parsing RecordFormatType from value: '" <> e
-           <> "'. Accepted values: CSV, JSON"
+           <> "'. Accepted values: csv, json"
 
 instance ToText RecordFormatType where
     toText = \case
diff --git a/amazonka-kinesis-firehose/gen/Network/AWS/Firehose/Types/Sum.hs b/amazonka-kinesis-firehose/gen/Network/AWS/Firehose/Types/Sum.hs
index 0f77ef553a6..73682d4eae4 100644
--- a/amazonka-kinesis-firehose/gen/Network/AWS/Firehose/Types/Sum.hs
+++ b/amazonka-kinesis-firehose/gen/Network/AWS/Firehose/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText CompressionFormat where
         "uncompressed" -> pure Uncompressed
         "zip" -> pure Zip
         e -> fromTextError $ "Failure parsing CompressionFormat from value: '" <> e
-           <> "'. Accepted values: GZIP, Snappy, UNCOMPRESSED, ZIP"
+           <> "'. Accepted values: gzip, snappy, uncompressed, zip"
 
 instance ToText CompressionFormat where
     toText = \case
@@ -66,7 +66,7 @@ instance FromText DeliveryStreamStatus where
         "creating" -> pure Creating
         "deleting" -> pure Deleting
         e -> fromTextError $ "Failure parsing DeliveryStreamStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, CREATING, DELETING"
+           <> "'. Accepted values: active, creating, deleting"
 
 instance ToText DeliveryStreamStatus where
     toText = \case
@@ -99,7 +99,7 @@ instance FromText ElasticsearchIndexRotationPeriod where
         "onemonth" -> pure OneMonth
         "oneweek" -> pure OneWeek
         e -> fromTextError $ "Failure parsing ElasticsearchIndexRotationPeriod from value: '" <> e
-           <> "'. Accepted values: NoRotation, OneDay, OneHour, OneMonth, OneWeek"
+           <> "'. Accepted values: norotation, oneday, onehour, onemonth, oneweek"
 
 instance ToText ElasticsearchIndexRotationPeriod where
     toText = \case
@@ -131,7 +131,7 @@ instance FromText ElasticsearchS3BackupMode where
         "alldocuments" -> pure AllDocuments
         "faileddocumentsonly" -> pure FailedDocumentsOnly
         e -> fromTextError $ "Failure parsing ElasticsearchS3BackupMode from value: '" <> e
-           <> "'. Accepted values: AllDocuments, FailedDocumentsOnly"
+           <> "'. Accepted values: alldocuments, faileddocumentsonly"
 
 instance ToText ElasticsearchS3BackupMode where
     toText = \case
@@ -158,7 +158,7 @@ instance FromText NoEncryptionConfig where
     parser = takeLowerText >>= \case
         "noencryption" -> pure NoEncryption
         e -> fromTextError $ "Failure parsing NoEncryptionConfig from value: '" <> e
-           <> "'. Accepted values: NoEncryption"
+           <> "'. Accepted values: noencryption"
 
 instance ToText NoEncryptionConfig where
     toText = \case
diff --git a/amazonka-kinesis/gen/Network/AWS/Kinesis/Types/Sum.hs b/amazonka-kinesis/gen/Network/AWS/Kinesis/Types/Sum.hs
index 953dff5ef05..52c4037a8d8 100644
--- a/amazonka-kinesis/gen/Network/AWS/Kinesis/Types/Sum.hs
+++ b/amazonka-kinesis/gen/Network/AWS/Kinesis/Types/Sum.hs
@@ -41,7 +41,7 @@ instance FromText MetricsName where
         "readprovisionedthroughputexceeded" -> pure ReadProvisionedThroughputExceeded
         "writeprovisionedthroughputexceeded" -> pure WriteProvisionedThroughputExceeded
         e -> fromTextError $ "Failure parsing MetricsName from value: '" <> e
-           <> "'. Accepted values: ALL, IncomingBytes, IncomingRecords, IteratorAgeMilliseconds, OutgoingBytes, OutgoingRecords, ReadProvisionedThroughputExceeded, WriteProvisionedThroughputExceeded"
+           <> "'. Accepted values: all, incomingbytes, incomingrecords, iteratoragemilliseconds, outgoingbytes, outgoingrecords, readprovisionedthroughputexceeded, writeprovisionedthroughputexceeded"
 
 instance ToText MetricsName where
     toText = \case
@@ -82,7 +82,7 @@ instance FromText ShardIteratorType where
         "latest" -> pure Latest
         "trim_horizon" -> pure TrimHorizon
         e -> fromTextError $ "Failure parsing ShardIteratorType from value: '" <> e
-           <> "'. Accepted values: AFTER_SEQUENCE_NUMBER, AT_SEQUENCE_NUMBER, AT_TIMESTAMP, LATEST, TRIM_HORIZON"
+           <> "'. Accepted values: after_sequence_number, at_sequence_number, at_timestamp, latest, trim_horizon"
 
 instance ToText ShardIteratorType where
     toText = \case
@@ -115,7 +115,7 @@ instance FromText StreamStatus where
         "deleting" -> pure Deleting
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing StreamStatus from value: '" <> e
-           <> "'. Accepted values: ACTIVE, CREATING, DELETING, UPDATING"
+           <> "'. Accepted values: active, creating, deleting, updating"
 
 instance ToText StreamStatus where
     toText = \case
diff --git a/amazonka-kms/gen/Network/AWS/KMS/Types/Sum.hs b/amazonka-kms/gen/Network/AWS/KMS/Types/Sum.hs
index 288532ec0d2..733d20d14b1 100644
--- a/amazonka-kms/gen/Network/AWS/KMS/Types/Sum.hs
+++ b/amazonka-kms/gen/Network/AWS/KMS/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText AlgorithmSpec where
         "rsaes_oaep_sha_256" -> pure RsaesOaepSha256
         "rsaes_pkcs1_v1_5" -> pure RsaesPKCS1V15
         e -> fromTextError $ "Failure parsing AlgorithmSpec from value: '" <> e
-           <> "'. Accepted values: RSAES_OAEP_SHA_1, RSAES_OAEP_SHA_256, RSAES_PKCS1_V1_5"
+           <> "'. Accepted values: rsaes_oaep_sha_1, rsaes_oaep_sha_256, rsaes_pkcs1_v1_5"
 
 instance ToText AlgorithmSpec where
     toText = \case
@@ -58,7 +58,7 @@ instance FromText DataKeySpec where
         "aes_128" -> pure AES128
         "aes_256" -> pure AES256
         e -> fromTextError $ "Failure parsing DataKeySpec from value: '" <> e
-           <> "'. Accepted values: AES_128, AES_256"
+           <> "'. Accepted values: aes_128, aes_256"
 
 instance ToText DataKeySpec where
     toText = \case
@@ -84,7 +84,7 @@ instance FromText ExpirationModelType where
         "key_material_does_not_expire" -> pure KeyMaterialDoesNotExpire
         "key_material_expires" -> pure KeyMaterialExpires
         e -> fromTextError $ "Failure parsing ExpirationModelType from value: '" <> e
-           <> "'. Accepted values: KEY_MATERIAL_DOES_NOT_EXPIRE, KEY_MATERIAL_EXPIRES"
+           <> "'. Accepted values: key_material_does_not_expire, key_material_expires"
 
 instance ToText ExpirationModelType where
     toText = \case
@@ -127,7 +127,7 @@ instance FromText GrantOperation where
         "reencryptto" -> pure ReEncryptTo
         "retiregrant" -> pure RetireGrant
         e -> fromTextError $ "Failure parsing GrantOperation from value: '" <> e
-           <> "'. Accepted values: CreateGrant, Decrypt, DescribeKey, Encrypt, GenerateDataKey, GenerateDataKeyWithoutPlaintext, ReEncryptFrom, ReEncryptTo, RetireGrant"
+           <> "'. Accepted values: creategrant, decrypt, describekey, encrypt, generatedatakey, generatedatakeywithoutplaintext, reencryptfrom, reencryptto, retiregrant"
 
 instance ToText GrantOperation where
     toText = \case
@@ -167,7 +167,7 @@ instance FromText KeyState where
         "pendingdeletion" -> pure PendingDeletion
         "pendingimport" -> pure PendingImport
         e -> fromTextError $ "Failure parsing KeyState from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled, PendingDeletion, PendingImport"
+           <> "'. Accepted values: disabled, enabled, pendingdeletion, pendingimport"
 
 instance ToText KeyState where
     toText = \case
@@ -193,7 +193,7 @@ instance FromText KeyUsageType where
     parser = takeLowerText >>= \case
         "encrypt_decrypt" -> pure EncryptDecrypt
         e -> fromTextError $ "Failure parsing KeyUsageType from value: '" <> e
-           <> "'. Accepted values: ENCRYPT_DECRYPT"
+           <> "'. Accepted values: encrypt_decrypt"
 
 instance ToText KeyUsageType where
     toText = \case
@@ -221,7 +221,7 @@ instance FromText OriginType where
         "aws_kms" -> pure AWSKMS
         "external" -> pure External
         e -> fromTextError $ "Failure parsing OriginType from value: '" <> e
-           <> "'. Accepted values: AWS_KMS, EXTERNAL"
+           <> "'. Accepted values: aws_kms, external"
 
 instance ToText OriginType where
     toText = \case
@@ -248,7 +248,7 @@ instance FromText WrappingKeySpec where
     parser = takeLowerText >>= \case
         "rsa_2048" -> pure Rsa2048
         e -> fromTextError $ "Failure parsing WrappingKeySpec from value: '" <> e
-           <> "'. Accepted values: RSA_2048"
+           <> "'. Accepted values: rsa_2048"
 
 instance ToText WrappingKeySpec where
     toText = \case
diff --git a/amazonka-lambda/gen/Network/AWS/Lambda/Types/Sum.hs b/amazonka-lambda/gen/Network/AWS/Lambda/Types/Sum.hs
index a006500d5fe..334f626d446 100644
--- a/amazonka-lambda/gen/Network/AWS/Lambda/Types/Sum.hs
+++ b/amazonka-lambda/gen/Network/AWS/Lambda/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText EventSourcePosition where
         "latest" -> pure Latest
         "trim_horizon" -> pure TrimHorizon
         e -> fromTextError $ "Failure parsing EventSourcePosition from value: '" <> e
-           <> "'. Accepted values: LATEST, TRIM_HORIZON"
+           <> "'. Accepted values: latest, trim_horizon"
 
 instance ToText EventSourcePosition where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText InvocationType where
         "event" -> pure Event
         "requestresponse" -> pure RequestResponse
         e -> fromTextError $ "Failure parsing InvocationType from value: '" <> e
-           <> "'. Accepted values: DryRun, Event, RequestResponse"
+           <> "'. Accepted values: dryrun, event, requestresponse"
 
 instance ToText InvocationType where
     toText = \case
@@ -84,7 +84,7 @@ instance FromText LogType where
         "none" -> pure None
         "tail" -> pure Tail
         e -> fromTextError $ "Failure parsing LogType from value: '" <> e
-           <> "'. Accepted values: None, Tail"
+           <> "'. Accepted values: none, tail"
 
 instance ToText LogType where
     toText = \case
diff --git a/amazonka-ml/gen/Network/AWS/MachineLearning/Types/Sum.hs b/amazonka-ml/gen/Network/AWS/MachineLearning/Types/Sum.hs
index ba718e0d469..c288fa06f47 100644
--- a/amazonka-ml/gen/Network/AWS/MachineLearning/Types/Sum.hs
+++ b/amazonka-ml/gen/Network/AWS/MachineLearning/Types/Sum.hs
@@ -77,7 +77,7 @@ instance FromText BatchPredictionFilterVariable where
         "name" -> pure BatchName
         "status" -> pure BatchStatus
         e -> fromTextError $ "Failure parsing BatchPredictionFilterVariable from value: '" <> e
-           <> "'. Accepted values: CreatedAt, DataSourceId, DataURI, IAMUser, LastUpdatedAt, MLModelId, Name, Status"
+           <> "'. Accepted values: createdat, datasourceid, datauri, iamuser, lastupdatedat, mlmodelid, name, status"
 
 instance ToText BatchPredictionFilterVariable where
     toText = \case
@@ -128,7 +128,7 @@ instance FromText DataSourceFilterVariable where
         "name" -> pure DataName
         "status" -> pure DataStatus
         e -> fromTextError $ "Failure parsing DataSourceFilterVariable from value: '" <> e
-           <> "'. Accepted values: CreatedAt, DataLocationS3, IAMUser, LastUpdatedAt, Name, Status"
+           <> "'. Accepted values: createdat, datalocations3, iamuser, lastupdatedat, name, status"
 
 instance ToText DataSourceFilterVariable where
     toText = \case
@@ -159,7 +159,7 @@ instance FromText DetailsAttributes where
         "algorithm" -> pure Algorithm
         "predictivemodeltype" -> pure PredictiveModelType
         e -> fromTextError $ "Failure parsing DetailsAttributes from value: '" <> e
-           <> "'. Accepted values: Algorithm, PredictiveModelType"
+           <> "'. Accepted values: algorithm, predictivemodeltype"
 
 instance ToText DetailsAttributes where
     toText = \case
@@ -198,7 +198,7 @@ instance FromText EntityStatus where
         "inprogress" -> pure ESInprogress
         "pending" -> pure ESPending
         e -> fromTextError $ "Failure parsing EntityStatus from value: '" <> e
-           <> "'. Accepted values: COMPLETED, DELETED, FAILED, INPROGRESS, PENDING"
+           <> "'. Accepted values: completed, deleted, failed, inprogress, pending"
 
 instance ToText EntityStatus where
     toText = \case
@@ -248,7 +248,7 @@ instance FromText EvaluationFilterVariable where
         "name" -> pure EvalName
         "status" -> pure EvalStatus
         e -> fromTextError $ "Failure parsing EvaluationFilterVariable from value: '" <> e
-           <> "'. Accepted values: CreatedAt, DataSourceId, DataURI, IAMUser, LastUpdatedAt, MLModelId, Name, Status"
+           <> "'. Accepted values: createdat, datasourceid, datauri, iamuser, lastupdatedat, mlmodelid, name, status"
 
 instance ToText EvaluationFilterVariable where
     toText = \case
@@ -296,7 +296,7 @@ instance FromText MLModelFilterVariable where
         "trainingdatasourceid" -> pure MLMFVTrainingDataSourceId
         "trainingdatauri" -> pure MLMFVTrainingDataURI
         e -> fromTextError $ "Failure parsing MLModelFilterVariable from value: '" <> e
-           <> "'. Accepted values: Algorithm, CreatedAt, IAMUser, LastUpdatedAt, MLModelType, Name, RealtimeEndpointStatus, Status, TrainingDataSourceId, TrainingDataURI"
+           <> "'. Accepted values: algorithm, createdat, iamuser, lastupdatedat, mlmodeltype, name, realtimeendpointstatus, status, trainingdatasourceid, trainingdatauri"
 
 instance ToText MLModelFilterVariable where
     toText = \case
@@ -332,7 +332,7 @@ instance FromText MLModelType where
         "multiclass" -> pure Multiclass
         "regression" -> pure Regression
         e -> fromTextError $ "Failure parsing MLModelType from value: '" <> e
-           <> "'. Accepted values: BINARY, MULTICLASS, REGRESSION"
+           <> "'. Accepted values: binary, multiclass, regression"
 
 instance ToText MLModelType where
     toText = \case
@@ -366,7 +366,7 @@ instance FromText RealtimeEndpointStatus where
         "ready" -> pure Ready
         "updating" -> pure Updating
         e -> fromTextError $ "Failure parsing RealtimeEndpointStatus from value: '" <> e
-           <> "'. Accepted values: FAILED, NONE, READY, UPDATING"
+           <> "'. Accepted values: failed, none, ready, updating"
 
 instance ToText RealtimeEndpointStatus where
     toText = \case
@@ -428,7 +428,7 @@ instance FromText TaggableResourceType where
         "evaluation" -> pure Evaluation
         "mlmodel" -> pure MLModel
         e -> fromTextError $ "Failure parsing TaggableResourceType from value: '" <> e
-           <> "'. Accepted values: BatchPrediction, DataSource, Evaluation, MLModel"
+           <> "'. Accepted values: batchprediction, datasource, evaluation, mlmodel"
 
 instance ToText TaggableResourceType where
     toText = \case
diff --git a/amazonka-opsworks/gen/Network/AWS/OpsWorks/Types/Sum.hs b/amazonka-opsworks/gen/Network/AWS/OpsWorks/Types/Sum.hs
index 1c33936006a..72258effad3 100644
--- a/amazonka-opsworks/gen/Network/AWS/OpsWorks/Types/Sum.hs
+++ b/amazonka-opsworks/gen/Network/AWS/OpsWorks/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText AppAttributesKeys where
         "documentroot" -> pure DocumentRoot
         "railsenv" -> pure RailsEnv
         e -> fromTextError $ "Failure parsing AppAttributesKeys from value: '" <> e
-           <> "'. Accepted values: AwsFlowRubySettings, AutoBundleOnDeploy, DocumentRoot, RailsEnv"
+           <> "'. Accepted values: awsflowrubysettings, autobundleondeploy, documentroot, railsenv"
 
 instance ToText AppAttributesKeys where
     toText = \case
@@ -271,7 +271,7 @@ instance FromText LayerAttributesKeys where
         "rubyversion" -> pure RubyVersion
         "rubygemsversion" -> pure RubygemsVersion
         e -> fromTextError $ "Failure parsing LayerAttributesKeys from value: '" <> e
-           <> "'. Accepted values: BundlerVersion, EcsClusterArn, EnableHaproxyStats, GangliaPassword, GangliaUrl, GangliaUser, HaproxyHealthCheckMethod, HaproxyHealthCheckUrl, HaproxyStatsPassword, HaproxyStatsUrl, HaproxyStatsUser, Jvm, JvmOptions, JvmVersion, JavaAppServer, JavaAppServerVersion, ManageBundler, MemcachedMemory, MysqlRootPassword, MysqlRootPasswordUbiquitous, NodejsVersion, PassengerVersion, RailsStack, RubyVersion, RubygemsVersion"
+           <> "'. Accepted values: bundlerversion, ecsclusterarn, enablehaproxystats, gangliapassword, gangliaurl, gangliauser, haproxyhealthcheckmethod, haproxyhealthcheckurl, haproxystatspassword, haproxystatsurl, haproxystatsuser, jvm, jvmoptions, jvmversion, javaappserver, javaappserverversion, managebundler, memcachedmemory, mysqlrootpassword, mysqlrootpasswordubiquitous, nodejsversion, passengerversion, railsstack, rubyversion, rubygemsversion"
 
 instance ToText LayerAttributesKeys where
     toText = \case
@@ -444,7 +444,7 @@ instance FromText StackAttributesKeys where
     parser = takeLowerText >>= \case
         "color" -> pure Color
         e -> fromTextError $ "Failure parsing StackAttributesKeys from value: '" <> e
-           <> "'. Accepted values: Color"
+           <> "'. Accepted values: color"
 
 instance ToText StackAttributesKeys where
     toText = \case
diff --git a/amazonka-redshift/gen/Network/AWS/Redshift/Types/Sum.hs b/amazonka-redshift/gen/Network/AWS/Redshift/Types/Sum.hs
index 21aa4ed39b2..d06cb937b43 100644
--- a/amazonka-redshift/gen/Network/AWS/Redshift/Types/Sum.hs
+++ b/amazonka-redshift/gen/Network/AWS/Redshift/Types/Sum.hs
@@ -93,7 +93,7 @@ instance FromText TableRestoreStatusType where
         "pending" -> pure Pending
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing TableRestoreStatusType from value: '" <> e
-           <> "'. Accepted values: CANCELED, FAILED, IN_PROGRESS, PENDING, SUCCEEDED"
+           <> "'. Accepted values: canceled, failed, in_progress, pending, succeeded"
 
 instance ToText TableRestoreStatusType where
     toText = \case
diff --git a/amazonka-route53-domains/gen/Network/AWS/Route53Domains/Types/Sum.hs b/amazonka-route53-domains/gen/Network/AWS/Route53Domains/Types/Sum.hs
index c0049f8b0c4..5b24d7f7533 100644
--- a/amazonka-route53-domains/gen/Network/AWS/Route53Domains/Types/Sum.hs
+++ b/amazonka-route53-domains/gen/Network/AWS/Route53Domains/Types/Sum.hs
@@ -35,7 +35,7 @@ instance FromText ContactType where
         "public_body" -> pure PublicBody
         "reseller" -> pure Reseller
         e -> fromTextError $ "Failure parsing ContactType from value: '" <> e
-           <> "'. Accepted values: ASSOCIATION, COMPANY, PERSON, PUBLIC_BODY, RESELLER"
+           <> "'. Accepted values: association, company, person, public_body, reseller"
 
 instance ToText ContactType where
     toText = \case
@@ -521,7 +521,7 @@ instance FromText CountryCode where
         "zm" -> pure ZM
         "zw" -> pure ZW
         e -> fromTextError $ "Failure parsing CountryCode from value: '" <> e
-           <> "'. Accepted values: AD, AE, AF, AG, AI, AL, AM, AN, AO, AQ, AR, AS, AT, AU, AW, AZ, BA, BB, BD, BE, BF, BG, BH, BI, BJ, BL, BM, BN, BO, BR, BS, BT, BW, BY, BZ, CA, CC, CD, CF, CG, CH, CI, CK, CL, CM, CN, CO, CR, CU, CV, CX, CY, CZ, DE, DJ, DK, DM, DO, DZ, EC, EE, EG, ER, ES, ET, FI, FJ, FK, FM, FO, FR, GA, GB, GD, GE, GH, GI, GL, GM, GN, GQ, GR, GT, GU, GW, GY, HK, HN, HR, HT, HU, IE, IL, IM, IN, IQ, IR, IS, IT, ID, JM, JO, JP, KE, KG, KH, KI, KM, KN, KP, KR, KW, KY, KZ, LA, LB, LC, LI, LK, LR, LS, LT, LU, LV, LY, MA, MC, MD, ME, MF, MG, MH, MK, ML, MM, MN, MO, MP, MR, MS, MT, MU, MV, MW, MX, MY, MZ, NA, NC, NE, NG, NI, NL, NO, NP, NR, NU, NZ, OM, PA, PE, PF, PG, PH, PK, PL, PM, PN, PR, PT, PW, PY, QA, RO, RS, RU, RW, SA, SB, SC, SD, SE, SG, SH, SI, SK, SL, SM, SN, SO, SR, ST, SV, SY, SZ, TC, TD, TG, TH, TJ, TK, TL, TM, TN, TO, TR, TT, TV, TW, TZ, UA, UG, US, UY, UZ, VA, VC, VE, VG, VI, VN, VU, WF, WS, YE, YT, ZA, ZM, ZW"
+           <> "'. Accepted values: ad, ae, af, ag, ai, al, am, an, ao, aq, ar, as, at, au, aw, az, ba, bb, bd, be, bf, bg, bh, bi, bj, bl, bm, bn, bo, br, bs, bt, bw, by, bz, ca, cc, cd, cf, cg, ch, ci, ck, cl, cm, cn, co, cr, cu, cv, cx, cy, cz, de, dj, dk, dm, do, dz, ec, ee, eg, er, es, et, fi, fj, fk, fm, fo, fr, ga, gb, gd, ge, gh, gi, gl, gm, gn, gq, gr, gt, gu, gw, gy, hk, hn, hr, ht, hu, ie, il, im, in, iq, ir, is, it, id, jm, jo, jp, ke, kg, kh, ki, km, kn, kp, kr, kw, ky, kz, la, lb, lc, li, lk, lr, ls, lt, lu, lv, ly, ma, mc, md, me, mf, mg, mh, mk, ml, mm, mn, mo, mp, mr, ms, mt, mu, mv, mw, mx, my, mz, na, nc, ne, ng, ni, nl, no, np, nr, nu, nz, om, pa, pe, pf, pg, ph, pk, pl, pm, pn, pr, pt, pw, py, qa, ro, rs, ru, rw, sa, sb, sc, sd, se, sg, sh, si, sk, sl, sm, sn, so, sr, st, sv, sy, sz, tc, td, tg, th, tj, tk, tl, tm, tn, to, tr, tt, tv, tw, tz, ua, ug, us, uy, uz, va, vc, ve, vg, vi, vn, vu, wf, ws, ye, yt, za, zm, zw"
 
 instance ToText CountryCode where
     toText = \case
@@ -789,7 +789,7 @@ instance FromText DomainAvailability where
         "unavailable_premium" -> pure UnavailablePremium
         "unavailable_restricted" -> pure UnavailableRestricted
         e -> fromTextError $ "Failure parsing DomainAvailability from value: '" <> e
-           <> "'. Accepted values: AVAILABLE, AVAILABLE_PREORDER, AVAILABLE_RESERVED, DONT_KNOW, RESERVED, UNAVAILABLE, UNAVAILABLE_PREMIUM, UNAVAILABLE_RESTRICTED"
+           <> "'. Accepted values: available, available_preorder, available_reserved, dont_know, reserved, unavailable, unavailable_premium, unavailable_restricted"
 
 instance ToText DomainAvailability where
     toText = \case
@@ -859,7 +859,7 @@ instance FromText ExtraParamName where
         "sg_id_number" -> pure SgIdNumber
         "vat_number" -> pure VatNumber
         e -> fromTextError $ "Failure parsing ExtraParamName from value: '" <> e
-           <> "'. Accepted values: AU_ID_NUMBER, AU_ID_TYPE, BIRTH_CITY, BIRTH_COUNTRY, BIRTH_DATE_IN_YYYY_MM_DD, BIRTH_DEPARTMENT, BRAND_NUMBER, CA_BUSINESS_ENTITY_TYPE, CA_LEGAL_TYPE, DOCUMENT_NUMBER, DUNS_NUMBER, ES_IDENTIFICATION, ES_IDENTIFICATION_TYPE, ES_LEGAL_FORM, FI_BUSINESS_NUMBER, FI_ID_NUMBER, IT_PIN, RU_PASSPORT_DATA, SE_ID_NUMBER, SG_ID_NUMBER, VAT_NUMBER"
+           <> "'. Accepted values: au_id_number, au_id_type, birth_city, birth_country, birth_date_in_yyyy_mm_dd, birth_department, brand_number, ca_business_entity_type, ca_legal_type, document_number, duns_number, es_identification, es_identification_type, es_legal_form, fi_business_number, fi_id_number, it_pin, ru_passport_data, se_id_number, sg_id_number, vat_number"
 
 instance ToText ExtraParamName where
     toText = \case
@@ -913,7 +913,7 @@ instance FromText OperationStatus where
         "submitted" -> pure Submitted
         "successful" -> pure Successful
         e -> fromTextError $ "Failure parsing OperationStatus from value: '" <> e
-           <> "'. Accepted values: ERROR, FAILED, IN_PROGRESS, SUBMITTED, SUCCESSFUL"
+           <> "'. Accepted values: error, failed, in_progress, submitted, successful"
 
 instance ToText OperationStatus where
     toText = \case
@@ -952,7 +952,7 @@ instance FromText OperationType where
         "update_domain_contact" -> pure UpdateDomainContact
         "update_nameserver" -> pure UpdateNameserver
         e -> fromTextError $ "Failure parsing OperationType from value: '" <> e
-           <> "'. Accepted values: CHANGE_PRIVACY_PROTECTION, DELETE_DOMAIN, DOMAIN_LOCK, REGISTER_DOMAIN, TRANSFER_IN_DOMAIN, UPDATE_DOMAIN_CONTACT, UPDATE_NAMESERVER"
+           <> "'. Accepted values: change_privacy_protection, delete_domain, domain_lock, register_domain, transfer_in_domain, update_domain_contact, update_nameserver"
 
 instance ToText OperationType where
     toText = \case
@@ -985,7 +985,7 @@ instance FromText ReachabilityStatus where
         "expired" -> pure Expired
         "pending" -> pure Pending
         e -> fromTextError $ "Failure parsing ReachabilityStatus from value: '" <> e
-           <> "'. Accepted values: DONE, EXPIRED, PENDING"
+           <> "'. Accepted values: done, expired, pending"
 
 instance ToText ReachabilityStatus where
     toText = \case
diff --git a/amazonka-route53/gen/Network/AWS/Route53/Types/Sum.hs b/amazonka-route53/gen/Network/AWS/Route53/Types/Sum.hs
index fbbf0962f79..23b80d32c05 100644
--- a/amazonka-route53/gen/Network/AWS/Route53/Types/Sum.hs
+++ b/amazonka-route53/gen/Network/AWS/Route53/Types/Sum.hs
@@ -32,7 +32,7 @@ instance FromText ChangeAction where
         "delete" -> pure Delete
         "upsert" -> pure Upsert
         e -> fromTextError $ "Failure parsing ChangeAction from value: '" <> e
-           <> "'. Accepted values: CREATE, DELETE, UPSERT"
+           <> "'. Accepted values: create, delete, upsert"
 
 instance ToText ChangeAction where
     toText = \case
@@ -59,7 +59,7 @@ instance FromText ChangeStatus where
         "insync" -> pure Insync
         "pending" -> pure Pending
         e -> fromTextError $ "Failure parsing ChangeStatus from value: '" <> e
-           <> "'. Accepted values: INSYNC, PENDING"
+           <> "'. Accepted values: insync, pending"
 
 instance ToText ChangeStatus where
     toText = \case
@@ -142,7 +142,7 @@ instance FromText ComparisonOperator where
         "lessthanorequaltothreshold" -> pure LessThanOrEqualToThreshold
         "lessthanthreshold" -> pure LessThanThreshold
         e -> fromTextError $ "Failure parsing ComparisonOperator from value: '" <> e
-           <> "'. Accepted values: GreaterThanOrEqualToThreshold, GreaterThanThreshold, LessThanOrEqualToThreshold, LessThanThreshold"
+           <> "'. Accepted values: greaterthanorequaltothreshold, greaterthanthreshold, lessthanorequaltothreshold, lessthanthreshold"
 
 instance ToText ComparisonOperator where
     toText = \case
@@ -170,7 +170,7 @@ instance FromText Failover where
         "primary" -> pure Primary
         "secondary" -> pure Secondary
         e -> fromTextError $ "Failure parsing Failover from value: '" <> e
-           <> "'. Accepted values: PRIMARY, SECONDARY"
+           <> "'. Accepted values: primary, secondary"
 
 instance ToText Failover where
     toText = \case
@@ -257,7 +257,7 @@ instance FromText HealthCheckType where
         "http_str_match" -> pure HTTPStrMatch
         "tcp" -> pure TCP
         e -> fromTextError $ "Failure parsing HealthCheckType from value: '" <> e
-           <> "'. Accepted values: CALCULATED, CLOUDWATCH_METRIC, HTTP, HTTPS, HTTPS_STR_MATCH, HTTP_STR_MATCH, TCP"
+           <> "'. Accepted values: calculated, cloudwatch_metric, http, https, https_str_match, http_str_match, tcp"
 
 instance ToText HealthCheckType where
     toText = \case
@@ -293,7 +293,7 @@ instance FromText InsufficientDataHealthStatus where
         "lastknownstatus" -> pure LastKnownStatus
         "unhealthy" -> pure Unhealthy
         e -> fromTextError $ "Failure parsing InsufficientDataHealthStatus from value: '" <> e
-           <> "'. Accepted values: Healthy, LastKnownStatus, Unhealthy"
+           <> "'. Accepted values: healthy, lastknownstatus, unhealthy"
 
 instance ToText InsufficientDataHealthStatus where
     toText = \case
@@ -339,7 +339,7 @@ instance FromText RecordType where
         "srv" -> pure Srv
         "txt" -> pure Txt
         e -> fromTextError $ "Failure parsing RecordType from value: '" <> e
-           <> "'. Accepted values: A, AAAA, CNAME, MX, NS, PTR, SOA, SPF, SRV, TXT"
+           <> "'. Accepted values: a, aaaa, cname, mx, ns, ptr, soa, spf, srv, txt"
 
 instance ToText RecordType where
     toText = \case
@@ -382,7 +382,7 @@ instance FromText Statistic where
         "samplecount" -> pure SampleCount
         "sum" -> pure Sum
         e -> fromTextError $ "Failure parsing Statistic from value: '" <> e
-           <> "'. Accepted values: Average, Maximum, Minimum, SampleCount, Sum"
+           <> "'. Accepted values: average, maximum, minimum, samplecount, sum"
 
 instance ToText Statistic where
     toText = \case
diff --git a/amazonka-s3/gen/Network/AWS/S3/Types/Sum.hs b/amazonka-s3/gen/Network/AWS/S3/Types/Sum.hs
index e0fb25d85c0..185a5cf1ec8 100644
--- a/amazonka-s3/gen/Network/AWS/S3/Types/Sum.hs
+++ b/amazonka-s3/gen/Network/AWS/S3/Types/Sum.hs
@@ -30,7 +30,7 @@ instance FromText BucketAccelerateStatus where
         "enabled" -> pure BASEnabled
         "suspended" -> pure BASSuspended
         e -> fromTextError $ "Failure parsing BucketAccelerateStatus from value: '" <> e
-           <> "'. Accepted values: Enabled, Suspended"
+           <> "'. Accepted values: enabled, suspended"
 
 instance ToText BucketAccelerateStatus where
     toText = \case
@@ -93,7 +93,7 @@ instance FromText BucketLogsPermission where
         "read" -> pure Read
         "write" -> pure Write
         e -> fromTextError $ "Failure parsing BucketLogsPermission from value: '" <> e
-           <> "'. Accepted values: FULL_CONTROL, READ, WRITE"
+           <> "'. Accepted values: full_control, read, write"
 
 instance ToText BucketLogsPermission where
     toText = \case
@@ -123,7 +123,7 @@ instance FromText BucketVersioningStatus where
         "enabled" -> pure BVSEnabled
         "suspended" -> pure BVSSuspended
         e -> fromTextError $ "Failure parsing BucketVersioningStatus from value: '" <> e
-           <> "'. Accepted values: Enabled, Suspended"
+           <> "'. Accepted values: enabled, suspended"
 
 instance ToText BucketVersioningStatus where
     toText = \case
@@ -194,7 +194,7 @@ instance FromText Event where
         "s3:objectremoved:deletemarkercreated" -> pure S3ObjectRemovedDeleteMarkerCreated
         "s3:reducedredundancylostobject" -> pure S3ReducedRedundancyLostObject
         e -> fromTextError $ "Failure parsing Event from value: '" <> e
-           <> "'. Accepted values: s3:ObjectCreated:*, s3:ObjectCreated:CompleteMultipartUpload, s3:ObjectCreated:Copy, s3:ObjectCreated:Post, s3:ObjectCreated:Put, s3:ObjectRemoved:*, s3:ObjectRemoved:Delete, s3:ObjectRemoved:DeleteMarkerCreated, s3:ReducedRedundancyLostObject"
+           <> "'. Accepted values: s3:objectcreated:*, s3:objectcreated:completemultipartupload, s3:objectcreated:copy, s3:objectcreated:post, s3:objectcreated:put, s3:objectremoved:*, s3:objectremoved:delete, s3:objectremoved:deletemarkercreated, s3:reducedredundancylostobject"
 
 instance ToText Event where
     toText = \case
@@ -230,7 +230,7 @@ instance FromText ExpirationStatus where
         "disabled" -> pure ESDisabled
         "enabled" -> pure ESEnabled
         e -> fromTextError $ "Failure parsing ExpirationStatus from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText ExpirationStatus where
     toText = \case
@@ -288,7 +288,7 @@ instance FromText MFADelete where
         "disabled" -> pure MDDisabled
         "enabled" -> pure MDEnabled
         e -> fromTextError $ "Failure parsing MFADelete from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText MFADelete where
     toText = \case
@@ -314,7 +314,7 @@ instance FromText MFADeleteStatus where
         "disabled" -> pure MDSDisabled
         "enabled" -> pure MDSEnabled
         e -> fromTextError $ "Failure parsing MFADeleteStatus from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText MFADeleteStatus where
     toText = \case
@@ -340,7 +340,7 @@ instance FromText MetadataDirective where
         "copy" -> pure Copy
         "replace" -> pure Replace
         e -> fromTextError $ "Failure parsing MetadataDirective from value: '" <> e
-           <> "'. Accepted values: COPY, REPLACE"
+           <> "'. Accepted values: copy, replace"
 
 instance ToText MetadataDirective where
     toText = \case
@@ -411,7 +411,7 @@ instance FromText ObjectStorageClass where
         "standard" -> pure OSCStandard
         "standard_ia" -> pure OSCStandardIA
         e -> fromTextError $ "Failure parsing ObjectStorageClass from value: '" <> e
-           <> "'. Accepted values: GLACIER, REDUCED_REDUNDANCY, STANDARD, STANDARD_IA"
+           <> "'. Accepted values: glacier, reduced_redundancy, standard, standard_ia"
 
 instance ToText ObjectStorageClass where
     toText = \case
@@ -437,7 +437,7 @@ instance FromText ObjectVersionStorageClass where
     parser = takeLowerText >>= \case
         "standard" -> pure OVSCStandard
         e -> fromTextError $ "Failure parsing ObjectVersionStorageClass from value: '" <> e
-           <> "'. Accepted values: STANDARD"
+           <> "'. Accepted values: standard"
 
 instance ToText ObjectVersionStorageClass where
     toText = \case
@@ -462,7 +462,7 @@ instance FromText Payer where
         "bucketowner" -> pure BucketOwner
         "requester" -> pure Requester
         e -> fromTextError $ "Failure parsing Payer from value: '" <> e
-           <> "'. Accepted values: BucketOwner, Requester"
+           <> "'. Accepted values: bucketowner, requester"
 
 instance ToText Payer where
     toText = \case
@@ -497,7 +497,7 @@ instance FromText Permission where
         "write" -> pure PWrite
         "write_acp" -> pure PWriteAcp
         e -> fromTextError $ "Failure parsing Permission from value: '" <> e
-           <> "'. Accepted values: FULL_CONTROL, READ, READ_ACP, WRITE, WRITE_ACP"
+           <> "'. Accepted values: full_control, read, read_acp, write, write_acp"
 
 instance ToText Permission where
     toText = \case
@@ -558,7 +558,7 @@ instance FromText ReplicationRuleStatus where
         "disabled" -> pure Disabled
         "enabled" -> pure Enabled
         e -> fromTextError $ "Failure parsing ReplicationRuleStatus from value: '" <> e
-           <> "'. Accepted values: Disabled, Enabled"
+           <> "'. Accepted values: disabled, enabled"
 
 instance ToText ReplicationRuleStatus where
     toText = \case
@@ -591,7 +591,7 @@ instance FromText ReplicationStatus where
         "pending" -> pure Pending
         "replica" -> pure Replica
         e -> fromTextError $ "Failure parsing ReplicationStatus from value: '" <> e
-           <> "'. Accepted values: COMPLETE, FAILED, PENDING, REPLICA"
+           <> "'. Accepted values: complete, failed, pending, replica"
 
 instance ToText ReplicationStatus where
     toText = \case
@@ -667,7 +667,7 @@ instance FromText ServerSideEncryption where
         "aes256" -> pure AES256
         "aws:kms" -> pure AWSKMS
         e -> fromTextError $ "Failure parsing ServerSideEncryption from value: '" <> e
-           <> "'. Accepted values: AES256, aws:kms"
+           <> "'. Accepted values: aes256, aws:kms"
 
 instance ToText ServerSideEncryption where
     toText = \case
@@ -698,7 +698,7 @@ instance FromText StorageClass where
         "standard" -> pure Standard
         "standard_ia" -> pure StandardIA
         e -> fromTextError $ "Failure parsing StorageClass from value: '" <> e
-           <> "'. Accepted values: REDUCED_REDUNDANCY, STANDARD, STANDARD_IA"
+           <> "'. Accepted values: reduced_redundancy, standard, standard_ia"
 
 instance ToText StorageClass where
     toText = \case
@@ -728,7 +728,7 @@ instance FromText TransitionStorageClass where
         "glacier" -> pure TSCGlacier
         "standard_ia" -> pure TSCStandardIA
         e -> fromTextError $ "Failure parsing TransitionStorageClass from value: '" <> e
-           <> "'. Accepted values: GLACIER, STANDARD_IA"
+           <> "'. Accepted values: glacier, standard_ia"
 
 instance ToText TransitionStorageClass where
     toText = \case
@@ -759,7 +759,7 @@ instance FromText Type where
         "canonicaluser" -> pure CanonicalUser
         "group" -> pure Group
         e -> fromTextError $ "Failure parsing Type from value: '" <> e
-           <> "'. Accepted values: AmazonCustomerByEmail, CanonicalUser, Group"
+           <> "'. Accepted values: amazoncustomerbyemail, canonicaluser, group"
 
 instance ToText Type where
     toText = \case
diff --git a/amazonka-servicecatalog/gen/Network/AWS/ServiceCatalog/Types/Sum.hs b/amazonka-servicecatalog/gen/Network/AWS/ServiceCatalog/Types/Sum.hs
index c4e470b1df2..cbff15c7baa 100644
--- a/amazonka-servicecatalog/gen/Network/AWS/ServiceCatalog/Types/Sum.hs
+++ b/amazonka-servicecatalog/gen/Network/AWS/ServiceCatalog/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText ProductViewFilterBy where
         "owner" -> pure Owner
         "producttype" -> pure ProductType
         e -> fromTextError $ "Failure parsing ProductViewFilterBy from value: '" <> e
-           <> "'. Accepted values: FullTextSearch, Owner, ProductType"
+           <> "'. Accepted values: fulltextsearch, owner, producttype"
 
 instance ToText ProductViewFilterBy where
     toText = \case
@@ -60,7 +60,7 @@ instance FromText ProductViewSortBy where
         "title" -> pure Title
         "versioncount" -> pure VersionCount
         e -> fromTextError $ "Failure parsing ProductViewSortBy from value: '" <> e
-           <> "'. Accepted values: CreationDate, Title, VersionCount"
+           <> "'. Accepted values: creationdate, title, versioncount"
 
 instance ToText ProductViewSortBy where
     toText = \case
@@ -89,7 +89,7 @@ instance FromText RecordStatus where
         "in_progress" -> pure InProgress
         "succeeded" -> pure Succeeded
         e -> fromTextError $ "Failure parsing RecordStatus from value: '" <> e
-           <> "'. Accepted values: ERROR, IN_PROGRESS, SUCCEEDED"
+           <> "'. Accepted values: error, in_progress, succeeded"
 
 instance ToText RecordStatus where
     toText = \case
@@ -116,7 +116,7 @@ instance FromText SortOrder where
         "ascending" -> pure Ascending
         "descending" -> pure Descending
         e -> fromTextError $ "Failure parsing SortOrder from value: '" <> e
-           <> "'. Accepted values: ASCENDING, DESCENDING"
+           <> "'. Accepted values: ascending, descending"
 
 instance ToText SortOrder where
     toText = \case
diff --git a/amazonka-ses/gen/Network/AWS/SES/Types/Sum.hs b/amazonka-ses/gen/Network/AWS/SES/Types/Sum.hs
index 766c3d8638d..2e5b31586e3 100644
--- a/amazonka-ses/gen/Network/AWS/SES/Types/Sum.hs
+++ b/amazonka-ses/gen/Network/AWS/SES/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText BehaviorOnMXFailure where
         "rejectmessage" -> pure RejectMessage
         "usedefaultvalue" -> pure UseDefaultValue
         e -> fromTextError $ "Failure parsing BehaviorOnMXFailure from value: '" <> e
-           <> "'. Accepted values: RejectMessage, UseDefaultValue"
+           <> "'. Accepted values: rejectmessage, usedefaultvalue"
 
 instance ToText BehaviorOnMXFailure where
     toText = \case
@@ -63,7 +63,7 @@ instance FromText BounceType where
         "temporaryfailure" -> pure BTTemporaryFailure
         "undefined" -> pure BTUndefined
         e -> fromTextError $ "Failure parsing BounceType from value: '" <> e
-           <> "'. Accepted values: ContentRejected, DoesNotExist, ExceededQuota, MessageTooLarge, TemporaryFailure, Undefined"
+           <> "'. Accepted values: contentrejected, doesnotexist, exceededquota, messagetoolarge, temporaryfailure, undefined"
 
 instance ToText BounceType where
     toText = \case
@@ -94,7 +94,7 @@ instance FromText CustomMailFromStatus where
         "success" -> pure CMFSSuccess
         "temporaryfailure" -> pure CMFSTemporaryFailure
         e -> fromTextError $ "Failure parsing CustomMailFromStatus from value: '" <> e
-           <> "'. Accepted values: Failed, Pending, Success, TemporaryFailure"
+           <> "'. Accepted values: failed, pending, success, temporaryfailure"
 
 instance ToText CustomMailFromStatus where
     toText = \case
@@ -154,7 +154,7 @@ instance FromText IdentityType where
         "domain" -> pure Domain
         "emailaddress" -> pure EmailAddress
         e -> fromTextError $ "Failure parsing IdentityType from value: '" <> e
-           <> "'. Accepted values: Domain, EmailAddress"
+           <> "'. Accepted values: domain, emailaddress"
 
 instance ToText IdentityType where
     toText = \case
@@ -177,7 +177,7 @@ instance FromText InvocationType where
         "event" -> pure Event
         "requestresponse" -> pure RequestResponse
         e -> fromTextError $ "Failure parsing InvocationType from value: '" <> e
-           <> "'. Accepted values: Event, RequestResponse"
+           <> "'. Accepted values: event, requestresponse"
 
 instance ToText InvocationType where
     toText = \case
@@ -205,7 +205,7 @@ instance FromText NotificationType where
         "complaint" -> pure Complaint
         "delivery" -> pure Delivery
         e -> fromTextError $ "Failure parsing NotificationType from value: '" <> e
-           <> "'. Accepted values: Bounce, Complaint, Delivery"
+           <> "'. Accepted values: bounce, complaint, delivery"
 
 instance ToText NotificationType where
     toText = \case
@@ -229,7 +229,7 @@ instance FromText ReceiptFilterPolicy where
         "allow" -> pure Allow
         "block" -> pure Block
         e -> fromTextError $ "Failure parsing ReceiptFilterPolicy from value: '" <> e
-           <> "'. Accepted values: Allow, Block"
+           <> "'. Accepted values: allow, block"
 
 instance ToText ReceiptFilterPolicy where
     toText = \case
@@ -255,7 +255,7 @@ instance FromText SNSActionEncoding where
         "base64" -> pure BASE64
         "utf-8" -> pure Utf8
         e -> fromTextError $ "Failure parsing SNSActionEncoding from value: '" <> e
-           <> "'. Accepted values: Base64, UTF-8"
+           <> "'. Accepted values: base64, utf-8"
 
 instance ToText SNSActionEncoding where
     toText = \case
@@ -279,7 +279,7 @@ instance FromText StopScope where
     parser = takeLowerText >>= \case
         "ruleset" -> pure RuleSet
         e -> fromTextError $ "Failure parsing StopScope from value: '" <> e
-           <> "'. Accepted values: RuleSet"
+           <> "'. Accepted values: ruleset"
 
 instance ToText StopScope where
     toText = \case
@@ -304,7 +304,7 @@ instance FromText TLSPolicy where
         "optional" -> pure Optional
         "require" -> pure Require
         e -> fromTextError $ "Failure parsing TLSPolicy from value: '" <> e
-           <> "'. Accepted values: Optional, Require"
+           <> "'. Accepted values: optional, require"
 
 instance ToText TLSPolicy where
     toText = \case
@@ -336,7 +336,7 @@ instance FromText VerificationStatus where
         "success" -> pure Success
         "temporaryfailure" -> pure TemporaryFailure
         e -> fromTextError $ "Failure parsing VerificationStatus from value: '" <> e
-           <> "'. Accepted values: Failed, NotStarted, Pending, Success, TemporaryFailure"
+           <> "'. Accepted values: failed, notstarted, pending, success, temporaryfailure"
 
 instance ToText VerificationStatus where
     toText = \case
diff --git a/amazonka-snowball/gen/Network/AWS/Snowball/Types/Sum.hs b/amazonka-snowball/gen/Network/AWS/Snowball/Types/Sum.hs
index 08f1486a122..e414824e41e 100644
--- a/amazonka-snowball/gen/Network/AWS/Snowball/Types/Sum.hs
+++ b/amazonka-snowball/gen/Network/AWS/Snowball/Types/Sum.hs
@@ -49,7 +49,7 @@ instance FromText JobState where
         "withaws" -> pure WithAWS
         "withcustomer" -> pure WithCustomer
         e -> fromTextError $ "Failure parsing JobState from value: '" <> e
-           <> "'. Accepted values: Cancelled, Complete, InProgress, InTransitToAWS, InTransitToCustomer, Listing, New, Pending, PreparingAppliance, PreparingShipment, WithAWS, WithCustomer"
+           <> "'. Accepted values: cancelled, complete, inprogress, intransittoaws, intransittocustomer, listing, new, pending, preparingappliance, preparingshipment, withaws, withcustomer"
 
 instance ToText JobState where
     toText = \case
@@ -88,7 +88,7 @@ instance FromText JobType where
         "export" -> pure Export
         "import" -> pure Import
         e -> fromTextError $ "Failure parsing JobType from value: '" <> e
-           <> "'. Accepted values: EXPORT, IMPORT"
+           <> "'. Accepted values: export, import"
 
 instance ToText JobType where
     toText = \case
@@ -121,7 +121,7 @@ instance FromText ShippingOption where
         "second_day" -> pure SecondDay
         "standard" -> pure Standard
         e -> fromTextError $ "Failure parsing ShippingOption from value: '" <> e
-           <> "'. Accepted values: EXPRESS, NEXT_DAY, SECOND_DAY, STANDARD"
+           <> "'. Accepted values: express, next_day, second_day, standard"
 
 instance ToText ShippingOption where
     toText = \case
@@ -154,7 +154,7 @@ instance FromText SnowballCapacity where
         "t50" -> pure T50
         "t80" -> pure T80
         e -> fromTextError $ "Failure parsing SnowballCapacity from value: '" <> e
-           <> "'. Accepted values: NoPreference, T50, T80"
+           <> "'. Accepted values: nopreference, t50, t80"
 
 instance ToText SnowballCapacity where
     toText = \case
diff --git a/amazonka-sqs/gen/Network/AWS/SQS/Types/Sum.hs b/amazonka-sqs/gen/Network/AWS/SQS/Types/Sum.hs
index 4c2bc86f9d1..9ee3cbeb294 100644
--- a/amazonka-sqs/gen/Network/AWS/SQS/Types/Sum.hs
+++ b/amazonka-sqs/gen/Network/AWS/SQS/Types/Sum.hs
@@ -35,7 +35,7 @@ instance FromText MessageAttribute where
         "senderid" -> pure SenderId
         "senttimestamp" -> pure SentTimestamp
         e -> fromTextError $ "Failure parsing MessageAttribute from value: '" <> e
-           <> "'. Accepted values: All, ApproximateFirstReceiveTimestamp, ApproximateReceiveCount, SenderId, SentTimestamp"
+           <> "'. Accepted values: all, approximatefirstreceivetimestamp, approximatereceivecount, senderid, senttimestamp"
 
 instance ToText MessageAttribute where
     toText = \case
@@ -86,7 +86,7 @@ instance FromText QueueAttributeName where
         "redrivepolicy" -> pure RedrivePolicy
         "visibilitytimeout" -> pure VisibilityTimeout
         e -> fromTextError $ "Failure parsing QueueAttributeName from value: '" <> e
-           <> "'. Accepted values: ApproximateNumberOfMessages, ApproximateNumberOfMessagesDelayed, ApproximateNumberOfMessagesNotVisible, CreatedTimestamp, DelaySeconds, LastModifiedTimestamp, MaximumMessageSize, MessageRetentionPeriod, Policy, QueueArn, ReceiveMessageWaitTimeSeconds, RedrivePolicy, VisibilityTimeout"
+           <> "'. Accepted values: approximatenumberofmessages, approximatenumberofmessagesdelayed, approximatenumberofmessagesnotvisible, createdtimestamp, delayseconds, lastmodifiedtimestamp, maximummessagesize, messageretentionperiod, policy, queuearn, receivemessagewaittimeseconds, redrivepolicy, visibilitytimeout"
 
 instance ToText QueueAttributeName where
     toText = \case
diff --git a/amazonka-ssm/gen/Network/AWS/SSM/Types/Sum.hs b/amazonka-ssm/gen/Network/AWS/SSM/Types/Sum.hs
index caebb6320fe..785f738aed5 100644
--- a/amazonka-ssm/gen/Network/AWS/SSM/Types/Sum.hs
+++ b/amazonka-ssm/gen/Network/AWS/SSM/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText AssociationFilterKey where
         "instanceid" -> pure AFKInstanceId
         "name" -> pure AFKName
         e -> fromTextError $ "Failure parsing AssociationFilterKey from value: '" <> e
-           <> "'. Accepted values: InstanceId, Name"
+           <> "'. Accepted values: instanceid, name"
 
 instance ToText AssociationFilterKey where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText AssociationStatusName where
         "pending" -> pure ASNPending
         "success" -> pure ASNSuccess
         e -> fromTextError $ "Failure parsing AssociationStatusName from value: '" <> e
-           <> "'. Accepted values: Failed, Pending, Success"
+           <> "'. Accepted values: failed, pending, success"
 
 instance ToText AssociationStatusName where
     toText = \case
@@ -89,7 +89,7 @@ instance FromText CommandFilterKey where
         "invokedbefore" -> pure CommandInvokedBefore
         "status" -> pure CommandStatus
         e -> fromTextError $ "Failure parsing CommandFilterKey from value: '" <> e
-           <> "'. Accepted values: InvokedAfter, InvokedBefore, Status"
+           <> "'. Accepted values: invokedafter, invokedbefore, status"
 
 instance ToText CommandFilterKey where
     toText = \case
@@ -126,7 +126,7 @@ instance FromText CommandInvocationStatus where
         "success" -> pure CISSuccess
         "timedout" -> pure CISTimedOut
         e -> fromTextError $ "Failure parsing CommandInvocationStatus from value: '" <> e
-           <> "'. Accepted values: Cancelled, Cancelling, Failed, InProgress, Pending, Success, TimedOut"
+           <> "'. Accepted values: cancelled, cancelling, failed, inprogress, pending, success, timedout"
 
 instance ToText CommandInvocationStatus where
     toText = \case
@@ -165,7 +165,7 @@ instance FromText CommandPluginStatus where
         "success" -> pure CPSSuccess
         "timedout" -> pure CPSTimedOut
         e -> fromTextError $ "Failure parsing CommandPluginStatus from value: '" <> e
-           <> "'. Accepted values: Cancelled, Failed, InProgress, Pending, Success, TimedOut"
+           <> "'. Accepted values: cancelled, failed, inprogress, pending, success, timedout"
 
 instance ToText CommandPluginStatus where
     toText = \case
@@ -205,7 +205,7 @@ instance FromText CommandStatus where
         "success" -> pure Success
         "timedout" -> pure TimedOut
         e -> fromTextError $ "Failure parsing CommandStatus from value: '" <> e
-           <> "'. Accepted values: Cancelled, Cancelling, Failed, InProgress, Pending, Success, TimedOut"
+           <> "'. Accepted values: cancelled, cancelling, failed, inprogress, pending, success, timedout"
 
 instance ToText CommandStatus where
     toText = \case
@@ -238,7 +238,7 @@ instance FromText DescribeActivationsFilterKeys where
         "defaultinstancename" -> pure DefaultInstanceName
         "iamrole" -> pure IAMRole
         e -> fromTextError $ "Failure parsing DescribeActivationsFilterKeys from value: '" <> e
-           <> "'. Accepted values: ActivationIds, DefaultInstanceName, IamRole"
+           <> "'. Accepted values: activationids, defaultinstancename, iamrole"
 
 instance ToText DescribeActivationsFilterKeys where
     toText = \case
@@ -267,7 +267,7 @@ instance FromText DocumentFilterKey where
         "owner" -> pure Owner
         "platformtypes" -> pure PlatformTypes
         e -> fromTextError $ "Failure parsing DocumentFilterKey from value: '" <> e
-           <> "'. Accepted values: Name, Owner, PlatformTypes"
+           <> "'. Accepted values: name, owner, platformtypes"
 
 instance ToText DocumentFilterKey where
     toText = \case
@@ -294,7 +294,7 @@ instance FromText DocumentHashType where
         "sha1" -> pure SHA1
         "sha256" -> pure SHA256
         e -> fromTextError $ "Failure parsing DocumentHashType from value: '" <> e
-           <> "'. Accepted values: Sha1, Sha256"
+           <> "'. Accepted values: sha1, sha256"
 
 instance ToText DocumentHashType where
     toText = \case
@@ -323,7 +323,7 @@ instance FromText DocumentParameterType where
         "string" -> pure String
         "stringlist" -> pure StringList
         e -> fromTextError $ "Failure parsing DocumentParameterType from value: '" <> e
-           <> "'. Accepted values: String, StringList"
+           <> "'. Accepted values: string, stringlist"
 
 instance ToText DocumentParameterType where
     toText = \case
@@ -347,7 +347,7 @@ instance FromText DocumentPermissionType where
     parser = takeLowerText >>= \case
         "share" -> pure Share
         e -> fromTextError $ "Failure parsing DocumentPermissionType from value: '" <> e
-           <> "'. Accepted values: Share"
+           <> "'. Accepted values: share"
 
 instance ToText DocumentPermissionType where
     toText = \case
@@ -374,7 +374,7 @@ instance FromText DocumentStatus where
         "creating" -> pure Creating
         "deleting" -> pure Deleting
         e -> fromTextError $ "Failure parsing DocumentStatus from value: '" <> e
-           <> "'. Accepted values: Active, Creating, Deleting"
+           <> "'. Accepted values: active, creating, deleting"
 
 instance ToText DocumentStatus where
     toText = \case
@@ -403,7 +403,7 @@ instance FromText Fault where
         "server" -> pure Server
         "unknown" -> pure Unknown
         e -> fromTextError $ "Failure parsing Fault from value: '" <> e
-           <> "'. Accepted values: Client, Server, Unknown"
+           <> "'. Accepted values: client, server, unknown"
 
 instance ToText Fault where
     toText = \case
@@ -440,7 +440,7 @@ instance FromText InstanceInformationFilterKey where
         "platformtypes" -> pure IIFKPlatformTypes
         "resourcetype" -> pure IIFKResourceType
         e -> fromTextError $ "Failure parsing InstanceInformationFilterKey from value: '" <> e
-           <> "'. Accepted values: ActivationIds, AgentVersion, IamRole, InstanceIds, PingStatus, PlatformTypes, ResourceType"
+           <> "'. Accepted values: activationids, agentversion, iamrole, instanceids, pingstatus, platformtypes, resourcetype"
 
 instance ToText InstanceInformationFilterKey where
     toText = \case
@@ -479,7 +479,7 @@ instance FromText NotificationEvent where
         "success" -> pure NESuccess
         "timedout" -> pure NETimedOut
         e -> fromTextError $ "Failure parsing NotificationEvent from value: '" <> e
-           <> "'. Accepted values: All, Cancelled, Failed, InProgress, Success, TimedOut"
+           <> "'. Accepted values: all, cancelled, failed, inprogress, success, timedout"
 
 instance ToText NotificationEvent where
     toText = \case
@@ -512,7 +512,7 @@ instance FromText NotificationType where
         "command" -> pure Command
         "invocation" -> pure Invocation
         e -> fromTextError $ "Failure parsing NotificationType from value: '" <> e
-           <> "'. Accepted values: Command, Invocation"
+           <> "'. Accepted values: command, invocation"
 
 instance ToText NotificationType where
     toText = \case
@@ -543,7 +543,7 @@ instance FromText PingStatus where
         "inactive" -> pure Inactive
         "online" -> pure Online
         e -> fromTextError $ "Failure parsing PingStatus from value: '" <> e
-           <> "'. Accepted values: ConnectionLost, Inactive, Online"
+           <> "'. Accepted values: connectionlost, inactive, online"
 
 instance ToText PingStatus where
     toText = \case
@@ -570,7 +570,7 @@ instance FromText PlatformType where
         "linux" -> pure Linux
         "windows" -> pure Windows
         e -> fromTextError $ "Failure parsing PlatformType from value: '" <> e
-           <> "'. Accepted values: Linux, Windows"
+           <> "'. Accepted values: linux, windows"
 
 instance ToText PlatformType where
     toText = \case
@@ -598,7 +598,7 @@ instance FromText ResourceType where
         "ec2instance" -> pure EC2Instance
         "managedinstance" -> pure ManagedInstance
         e -> fromTextError $ "Failure parsing ResourceType from value: '" <> e
-           <> "'. Accepted values: Document, EC2Instance, ManagedInstance"
+           <> "'. Accepted values: document, ec2instance, managedinstance"
 
 instance ToText ResourceType where
     toText = \case
@@ -623,7 +623,7 @@ instance FromText ResourceTypeForTagging where
     parser = takeLowerText >>= \case
         "managedinstance" -> pure RTFTManagedInstance
         e -> fromTextError $ "Failure parsing ResourceTypeForTagging from value: '" <> e
-           <> "'. Accepted values: ManagedInstance"
+           <> "'. Accepted values: managedinstance"
 
 instance ToText ResourceTypeForTagging where
     toText = \case
diff --git a/amazonka-swf/gen/Network/AWS/SWF/Types/Sum.hs b/amazonka-swf/gen/Network/AWS/SWF/Types/Sum.hs
index b71ccad74a4..32b9cc08f16 100644
--- a/amazonka-swf/gen/Network/AWS/SWF/Types/Sum.hs
+++ b/amazonka-swf/gen/Network/AWS/SWF/Types/Sum.hs
@@ -33,7 +33,7 @@ instance FromText ActivityTaskTimeoutType where
         "schedule_to_start" -> pure ATTTScheduleToStart
         "start_to_close" -> pure ATTTStartToClose
         e -> fromTextError $ "Failure parsing ActivityTaskTimeoutType from value: '" <> e
-           <> "'. Accepted values: HEARTBEAT, SCHEDULE_TO_CLOSE, SCHEDULE_TO_START, START_TO_CLOSE"
+           <> "'. Accepted values: heartbeat, schedule_to_close, schedule_to_start, start_to_close"
 
 instance ToText ActivityTaskTimeoutType where
     toText = \case
@@ -61,7 +61,7 @@ instance FromText CancelTimerFailedCause where
         "operation_not_permitted" -> pure CTFCOperationNotPermitted
         "timer_id_unknown" -> pure CTFCTimerIdUnknown
         e -> fromTextError $ "Failure parsing CancelTimerFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, TIMER_ID_UNKNOWN"
+           <> "'. Accepted values: operation_not_permitted, timer_id_unknown"
 
 instance ToText CancelTimerFailedCause where
     toText = \case
@@ -87,7 +87,7 @@ instance FromText CancelWorkflowExecutionFailedCause where
         "operation_not_permitted" -> pure COperationNotPermitted
         "unhandled_decision" -> pure CUnhandledDecision
         e -> fromTextError $ "Failure parsing CancelWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, UNHANDLED_DECISION"
+           <> "'. Accepted values: operation_not_permitted, unhandled_decision"
 
 instance ToText CancelWorkflowExecutionFailedCause where
     toText = \case
@@ -115,7 +115,7 @@ instance FromText ChildPolicy where
         "request_cancel" -> pure RequestCancel
         "terminate" -> pure Terminate
         e -> fromTextError $ "Failure parsing ChildPolicy from value: '" <> e
-           <> "'. Accepted values: ABANDON, REQUEST_CANCEL, TERMINATE"
+           <> "'. Accepted values: abandon, request_cancel, terminate"
 
 instance ToText ChildPolicy where
     toText = \case
@@ -153,7 +153,7 @@ instance FromText CloseStatus where
         "terminated" -> pure Terminated
         "timed_out" -> pure TimedOut
         e -> fromTextError $ "Failure parsing CloseStatus from value: '" <> e
-           <> "'. Accepted values: CANCELED, COMPLETED, CONTINUED_AS_NEW, FAILED, TERMINATED, TIMED_OUT"
+           <> "'. Accepted values: canceled, completed, continued_as_new, failed, terminated, timed_out"
 
 instance ToText CloseStatus where
     toText = \case
@@ -186,7 +186,7 @@ instance FromText CompleteWorkflowExecutionFailedCause where
         "operation_not_permitted" -> pure CWEFCOperationNotPermitted
         "unhandled_decision" -> pure CWEFCUnhandledDecision
         e -> fromTextError $ "Failure parsing CompleteWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, UNHANDLED_DECISION"
+           <> "'. Accepted values: operation_not_permitted, unhandled_decision"
 
 instance ToText CompleteWorkflowExecutionFailedCause where
     toText = \case
@@ -226,7 +226,7 @@ instance FromText ContinueAsNewWorkflowExecutionFailedCause where
         "workflow_type_deprecated" -> pure CANWEFCWorkflowTypeDeprecated
         "workflow_type_does_not_exist" -> pure CANWEFCWorkflowTypeDoesNotExist
         e -> fromTextError $ "Failure parsing ContinueAsNewWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: CONTINUE_AS_NEW_WORKFLOW_EXECUTION_RATE_EXCEEDED, DEFAULT_CHILD_POLICY_UNDEFINED, DEFAULT_EXECUTION_START_TO_CLOSE_TIMEOUT_UNDEFINED, DEFAULT_TASK_LIST_UNDEFINED, DEFAULT_TASK_START_TO_CLOSE_TIMEOUT_UNDEFINED, OPERATION_NOT_PERMITTED, UNHANDLED_DECISION, WORKFLOW_TYPE_DEPRECATED, WORKFLOW_TYPE_DOES_NOT_EXIST"
+           <> "'. Accepted values: continue_as_new_workflow_execution_rate_exceeded, default_child_policy_undefined, default_execution_start_to_close_timeout_undefined, default_task_list_undefined, default_task_start_to_close_timeout_undefined, operation_not_permitted, unhandled_decision, workflow_type_deprecated, workflow_type_does_not_exist"
 
 instance ToText ContinueAsNewWorkflowExecutionFailedCause where
     toText = \case
@@ -257,7 +257,7 @@ instance FromText DecisionTaskTimeoutType where
     parser = takeLowerText >>= \case
         "start_to_close" -> pure StartToClose
         e -> fromTextError $ "Failure parsing DecisionTaskTimeoutType from value: '" <> e
-           <> "'. Accepted values: START_TO_CLOSE"
+           <> "'. Accepted values: start_to_close"
 
 instance ToText DecisionTaskTimeoutType where
     toText = \case
@@ -304,7 +304,7 @@ instance FromText DecisionType where
         "startchildworkflowexecution" -> pure StartChildWorkflowExecution
         "starttimer" -> pure StartTimer
         e -> fromTextError $ "Failure parsing DecisionType from value: '" <> e
-           <> "'. Accepted values: CancelTimer, CancelWorkflowExecution, CompleteWorkflowExecution, ContinueAsNewWorkflowExecution, FailWorkflowExecution, RecordMarker, RequestCancelActivityTask, RequestCancelExternalWorkflowExecution, ScheduleActivityTask, ScheduleLambdaFunction, SignalExternalWorkflowExecution, StartChildWorkflowExecution, StartTimer"
+           <> "'. Accepted values: canceltimer, cancelworkflowexecution, completeworkflowexecution, continueasnewworkflowexecution, failworkflowexecution, recordmarker, requestcancelactivitytask, requestcancelexternalworkflowexecution, scheduleactivitytask, schedulelambdafunction, signalexternalworkflowexecution, startchildworkflowexecution, starttimer"
 
 instance ToText DecisionType where
     toText = \case
@@ -445,7 +445,7 @@ instance FromText EventType where
         "workflowexecutionterminated" -> pure WorkflowExecutionTerminated
         "workflowexecutiontimedout" -> pure WorkflowExecutionTimedOut
         e -> fromTextError $ "Failure parsing EventType from value: '" <> e
-           <> "'. Accepted values: ActivityTaskCancelRequested, ActivityTaskCanceled, ActivityTaskCompleted, ActivityTaskFailed, ActivityTaskScheduled, ActivityTaskStarted, ActivityTaskTimedOut, CancelTimerFailed, CancelWorkflowExecutionFailed, ChildWorkflowExecutionCanceled, ChildWorkflowExecutionCompleted, ChildWorkflowExecutionFailed, ChildWorkflowExecutionStarted, ChildWorkflowExecutionTerminated, ChildWorkflowExecutionTimedOut, CompleteWorkflowExecutionFailed, ContinueAsNewWorkflowExecutionFailed, DecisionTaskCompleted, DecisionTaskScheduled, DecisionTaskStarted, DecisionTaskTimedOut, ExternalWorkflowExecutionCancelRequested, ExternalWorkflowExecutionSignaled, FailWorkflowExecutionFailed, LambdaFunctionCompleted, LambdaFunctionFailed, LambdaFunctionScheduled, LambdaFunctionStarted, LambdaFunctionTimedOut, MarkerRecorded, RecordMarkerFailed, RequestCancelActivityTaskFailed, RequestCancelExternalWorkflowExecutionFailed, RequestCancelExternalWorkflowExecutionInitiated, ScheduleActivityTaskFailed, ScheduleLambdaFunctionFailed, SignalExternalWorkflowExecutionFailed, SignalExternalWorkflowExecutionInitiated, StartChildWorkflowExecutionFailed, StartChildWorkflowExecutionInitiated, StartLambdaFunctionFailed, StartTimerFailed, TimerCanceled, TimerFired, TimerStarted, WorkflowExecutionCancelRequested, WorkflowExecutionCanceled, WorkflowExecutionCompleted, WorkflowExecutionContinuedAsNew, WorkflowExecutionFailed, WorkflowExecutionSignaled, WorkflowExecutionStarted, WorkflowExecutionTerminated, WorkflowExecutionTimedOut"
+           <> "'. Accepted values: activitytaskcancelrequested, activitytaskcanceled, activitytaskcompleted, activitytaskfailed, activitytaskscheduled, activitytaskstarted, activitytasktimedout, canceltimerfailed, cancelworkflowexecutionfailed, childworkflowexecutioncanceled, childworkflowexecutioncompleted, childworkflowexecutionfailed, childworkflowexecutionstarted, childworkflowexecutionterminated, childworkflowexecutiontimedout, completeworkflowexecutionfailed, continueasnewworkflowexecutionfailed, decisiontaskcompleted, decisiontaskscheduled, decisiontaskstarted, decisiontasktimedout, externalworkflowexecutioncancelrequested, externalworkflowexecutionsignaled, failworkflowexecutionfailed, lambdafunctioncompleted, lambdafunctionfailed, lambdafunctionscheduled, lambdafunctionstarted, lambdafunctiontimedout, markerrecorded, recordmarkerfailed, requestcancelactivitytaskfailed, requestcancelexternalworkflowexecutionfailed, requestcancelexternalworkflowexecutioninitiated, scheduleactivitytaskfailed, schedulelambdafunctionfailed, signalexternalworkflowexecutionfailed, signalexternalworkflowexecutioninitiated, startchildworkflowexecutionfailed, startchildworkflowexecutioninitiated, startlambdafunctionfailed, starttimerfailed, timercanceled, timerfired, timerstarted, workflowexecutioncancelrequested, workflowexecutioncanceled, workflowexecutioncompleted, workflowexecutioncontinuedasnew, workflowexecutionfailed, workflowexecutionsignaled, workflowexecutionstarted, workflowexecutionterminated, workflowexecutiontimedout"
 
 instance ToText EventType where
     toText = \case
@@ -523,7 +523,7 @@ instance FromText ExecutionStatus where
         "closed" -> pure Closed
         "open" -> pure Open
         e -> fromTextError $ "Failure parsing ExecutionStatus from value: '" <> e
-           <> "'. Accepted values: CLOSED, OPEN"
+           <> "'. Accepted values: closed, open"
 
 instance ToText ExecutionStatus where
     toText = \case
@@ -549,7 +549,7 @@ instance FromText FailWorkflowExecutionFailedCause where
         "operation_not_permitted" -> pure FWEFCOperationNotPermitted
         "unhandled_decision" -> pure FWEFCUnhandledDecision
         e -> fromTextError $ "Failure parsing FailWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, UNHANDLED_DECISION"
+           <> "'. Accepted values: operation_not_permitted, unhandled_decision"
 
 instance ToText FailWorkflowExecutionFailedCause where
     toText = \case
@@ -573,7 +573,7 @@ instance FromText LambdaFunctionTimeoutType where
     parser = takeLowerText >>= \case
         "start_to_close" -> pure LFTTStartToClose
         e -> fromTextError $ "Failure parsing LambdaFunctionTimeoutType from value: '" <> e
-           <> "'. Accepted values: START_TO_CLOSE"
+           <> "'. Accepted values: start_to_close"
 
 instance ToText LambdaFunctionTimeoutType where
     toText = \case
@@ -596,7 +596,7 @@ instance FromText RecordMarkerFailedCause where
     parser = takeLowerText >>= \case
         "operation_not_permitted" -> pure OperationNotPermitted
         e -> fromTextError $ "Failure parsing RecordMarkerFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED"
+           <> "'. Accepted values: operation_not_permitted"
 
 instance ToText RecordMarkerFailedCause where
     toText = \case
@@ -621,7 +621,7 @@ instance FromText RegistrationStatus where
         "deprecated" -> pure Deprecated
         "registered" -> pure Registered
         e -> fromTextError $ "Failure parsing RegistrationStatus from value: '" <> e
-           <> "'. Accepted values: DEPRECATED, REGISTERED"
+           <> "'. Accepted values: deprecated, registered"
 
 instance ToText RegistrationStatus where
     toText = \case
@@ -650,7 +650,7 @@ instance FromText RequestCancelActivityTaskFailedCause where
         "activity_id_unknown" -> pure RCATFCActivityIdUnknown
         "operation_not_permitted" -> pure RCATFCOperationNotPermitted
         e -> fromTextError $ "Failure parsing RequestCancelActivityTaskFailedCause from value: '" <> e
-           <> "'. Accepted values: ACTIVITY_ID_UNKNOWN, OPERATION_NOT_PERMITTED"
+           <> "'. Accepted values: activity_id_unknown, operation_not_permitted"
 
 instance ToText RequestCancelActivityTaskFailedCause where
     toText = \case
@@ -678,7 +678,7 @@ instance FromText RequestCancelExternalWorkflowExecutionFailedCause where
         "request_cancel_external_workflow_execution_rate_exceeded" -> pure RCEWEFCRequestCancelExternalWorkflowExecutionRateExceeded
         "unknown_external_workflow_execution" -> pure RCEWEFCUnknownExternalWorkflowExecution
         e -> fromTextError $ "Failure parsing RequestCancelExternalWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, REQUEST_CANCEL_EXTERNAL_WORKFLOW_EXECUTION_RATE_EXCEEDED, UNKNOWN_EXTERNAL_WORKFLOW_EXECUTION"
+           <> "'. Accepted values: operation_not_permitted, request_cancel_external_workflow_execution_rate_exceeded, unknown_external_workflow_execution"
 
 instance ToText RequestCancelExternalWorkflowExecutionFailedCause where
     toText = \case
@@ -723,7 +723,7 @@ instance FromText ScheduleActivityTaskFailedCause where
         "open_activities_limit_exceeded" -> pure SATFCOpenActivitiesLimitExceeded
         "operation_not_permitted" -> pure SATFCOperationNotPermitted
         e -> fromTextError $ "Failure parsing ScheduleActivityTaskFailedCause from value: '" <> e
-           <> "'. Accepted values: ACTIVITY_CREATION_RATE_EXCEEDED, ACTIVITY_ID_ALREADY_IN_USE, ACTIVITY_TYPE_DEPRECATED, ACTIVITY_TYPE_DOES_NOT_EXIST, DEFAULT_HEARTBEAT_TIMEOUT_UNDEFINED, DEFAULT_SCHEDULE_TO_CLOSE_TIMEOUT_UNDEFINED, DEFAULT_SCHEDULE_TO_START_TIMEOUT_UNDEFINED, DEFAULT_START_TO_CLOSE_TIMEOUT_UNDEFINED, DEFAULT_TASK_LIST_UNDEFINED, OPEN_ACTIVITIES_LIMIT_EXCEEDED, OPERATION_NOT_PERMITTED"
+           <> "'. Accepted values: activity_creation_rate_exceeded, activity_id_already_in_use, activity_type_deprecated, activity_type_does_not_exist, default_heartbeat_timeout_undefined, default_schedule_to_close_timeout_undefined, default_schedule_to_start_timeout_undefined, default_start_to_close_timeout_undefined, default_task_list_undefined, open_activities_limit_exceeded, operation_not_permitted"
 
 instance ToText ScheduleActivityTaskFailedCause where
     toText = \case
@@ -762,7 +762,7 @@ instance FromText ScheduleLambdaFunctionFailedCause where
         "lambda_service_not_available_in_region" -> pure LambdaServiceNotAvailableInRegion
         "open_lambda_functions_limit_exceeded" -> pure OpenLambdaFunctionsLimitExceeded
         e -> fromTextError $ "Failure parsing ScheduleLambdaFunctionFailedCause from value: '" <> e
-           <> "'. Accepted values: ID_ALREADY_IN_USE, LAMBDA_FUNCTION_CREATION_RATE_EXCEEDED, LAMBDA_SERVICE_NOT_AVAILABLE_IN_REGION, OPEN_LAMBDA_FUNCTIONS_LIMIT_EXCEEDED"
+           <> "'. Accepted values: id_already_in_use, lambda_function_creation_rate_exceeded, lambda_service_not_available_in_region, open_lambda_functions_limit_exceeded"
 
 instance ToText ScheduleLambdaFunctionFailedCause where
     toText = \case
@@ -792,7 +792,7 @@ instance FromText SignalExternalWorkflowExecutionFailedCause where
         "signal_external_workflow_execution_rate_exceeded" -> pure SEWEFCSignalExternalWorkflowExecutionRateExceeded
         "unknown_external_workflow_execution" -> pure SEWEFCUnknownExternalWorkflowExecution
         e -> fromTextError $ "Failure parsing SignalExternalWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: OPERATION_NOT_PERMITTED, SIGNAL_EXTERNAL_WORKFLOW_EXECUTION_RATE_EXCEEDED, UNKNOWN_EXTERNAL_WORKFLOW_EXECUTION"
+           <> "'. Accepted values: operation_not_permitted, signal_external_workflow_execution_rate_exceeded, unknown_external_workflow_execution"
 
 instance ToText SignalExternalWorkflowExecutionFailedCause where
     toText = \case
@@ -837,7 +837,7 @@ instance FromText StartChildWorkflowExecutionFailedCause where
         "workflow_type_deprecated" -> pure SCWEFCWorkflowTypeDeprecated
         "workflow_type_does_not_exist" -> pure SCWEFCWorkflowTypeDoesNotExist
         e -> fromTextError $ "Failure parsing StartChildWorkflowExecutionFailedCause from value: '" <> e
-           <> "'. Accepted values: CHILD_CREATION_RATE_EXCEEDED, DEFAULT_CHILD_POLICY_UNDEFINED, DEFAULT_EXECUTION_START_TO_CLOSE_TIMEOUT_UNDEFINED, DEFAULT_TASK_LIST_UNDEFINED, DEFAULT_TASK_START_TO_CLOSE_TIMEOUT_UNDEFINED, OPEN_CHILDREN_LIMIT_EXCEEDED, OPEN_WORKFLOWS_LIMIT_EXCEEDED, OPERATION_NOT_PERMITTED, WORKFLOW_ALREADY_RUNNING, WORKFLOW_TYPE_DEPRECATED, WORKFLOW_TYPE_DOES_NOT_EXIST"
+           <> "'. Accepted values: child_creation_rate_exceeded, default_child_policy_undefined, default_execution_start_to_close_timeout_undefined, default_task_list_undefined, default_task_start_to_close_timeout_undefined, open_children_limit_exceeded, open_workflows_limit_exceeded, operation_not_permitted, workflow_already_running, workflow_type_deprecated, workflow_type_does_not_exist"
 
 instance ToText StartChildWorkflowExecutionFailedCause where
     toText = \case
@@ -870,7 +870,7 @@ instance FromText StartLambdaFunctionFailedCause where
     parser = takeLowerText >>= \case
         "assume_role_failed" -> pure AssumeRoleFailed
         e -> fromTextError $ "Failure parsing StartLambdaFunctionFailedCause from value: '" <> e
-           <> "'. Accepted values: ASSUME_ROLE_FAILED"
+           <> "'. Accepted values: assume_role_failed"
 
 instance ToText StartLambdaFunctionFailedCause where
     toText = \case
@@ -899,7 +899,7 @@ instance FromText StartTimerFailedCause where
         "timer_creation_rate_exceeded" -> pure STFCTimerCreationRateExceeded
         "timer_id_already_in_use" -> pure STFCTimerIdAlreadyInUse
         e -> fromTextError $ "Failure parsing StartTimerFailedCause from value: '" <> e
-           <> "'. Accepted values: OPEN_TIMERS_LIMIT_EXCEEDED, OPERATION_NOT_PERMITTED, TIMER_CREATION_RATE_EXCEEDED, TIMER_ID_ALREADY_IN_USE"
+           <> "'. Accepted values: open_timers_limit_exceeded, operation_not_permitted, timer_creation_rate_exceeded, timer_id_already_in_use"
 
 instance ToText StartTimerFailedCause where
     toText = \case
@@ -925,7 +925,7 @@ instance FromText WorkflowExecutionCancelRequestedCause where
     parser = takeLowerText >>= \case
         "child_policy_applied" -> pure ChildPolicyApplied
         e -> fromTextError $ "Failure parsing WorkflowExecutionCancelRequestedCause from value: '" <> e
-           <> "'. Accepted values: CHILD_POLICY_APPLIED"
+           <> "'. Accepted values: child_policy_applied"
 
 instance ToText WorkflowExecutionCancelRequestedCause where
     toText = \case
@@ -952,7 +952,7 @@ instance FromText WorkflowExecutionTerminatedCause where
         "event_limit_exceeded" -> pure WETCEventLimitExceeded
         "operator_initiated" -> pure WETCOperatorInitiated
         e -> fromTextError $ "Failure parsing WorkflowExecutionTerminatedCause from value: '" <> e
-           <> "'. Accepted values: CHILD_POLICY_APPLIED, EVENT_LIMIT_EXCEEDED, OPERATOR_INITIATED"
+           <> "'. Accepted values: child_policy_applied, event_limit_exceeded, operator_initiated"
 
 instance ToText WorkflowExecutionTerminatedCause where
     toText = \case
@@ -977,7 +977,7 @@ instance FromText WorkflowExecutionTimeoutType where
     parser = takeLowerText >>= \case
         "start_to_close" -> pure WETTStartToClose
         e -> fromTextError $ "Failure parsing WorkflowExecutionTimeoutType from value: '" <> e
-           <> "'. Accepted values: START_TO_CLOSE"
+           <> "'. Accepted values: start_to_close"
 
 instance ToText WorkflowExecutionTimeoutType where
     toText = \case
diff --git a/amazonka-waf/gen/Network/AWS/WAF/Types/Sum.hs b/amazonka-waf/gen/Network/AWS/WAF/Types/Sum.hs
index 8df1e9cd207..e1c997e3bb6 100644
--- a/amazonka-waf/gen/Network/AWS/WAF/Types/Sum.hs
+++ b/amazonka-waf/gen/Network/AWS/WAF/Types/Sum.hs
@@ -29,7 +29,7 @@ instance FromText ChangeAction where
         "delete" -> pure Delete
         "insert" -> pure Insert
         e -> fromTextError $ "Failure parsing ChangeAction from value: '" <> e
-           <> "'. Accepted values: DELETE, INSERT"
+           <> "'. Accepted values: delete, insert"
 
 instance ToText ChangeAction where
     toText = \case
@@ -57,7 +57,7 @@ instance FromText ChangeTokenStatus where
         "pending" -> pure Pending
         "provisioned" -> pure Provisioned
         e -> fromTextError $ "Failure parsing ChangeTokenStatus from value: '" <> e
-           <> "'. Accepted values: INSYNC, PENDING, PROVISIONED"
+           <> "'. Accepted values: insync, pending, provisioned"
 
 instance ToText ChangeTokenStatus where
     toText = \case
@@ -92,7 +92,7 @@ instance FromText ComparisonOperator where
         "lt" -> pure LT'
         "ne" -> pure NE
         e -> fromTextError $ "Failure parsing ComparisonOperator from value: '" <> e
-           <> "'. Accepted values: EQ, GE, GT, LE, LT, NE"
+           <> "'. Accepted values: eq, ge, gt, le, lt, ne"
 
 instance ToText ComparisonOperator where
     toText = \case
@@ -123,7 +123,7 @@ instance FromText IPSetDescriptorType where
     parser = takeLowerText >>= \case
         "ipv4" -> pure IPV4
         e -> fromTextError $ "Failure parsing IPSetDescriptorType from value: '" <> e
-           <> "'. Accepted values: IPV4"
+           <> "'. Accepted values: ipv4"
 
 instance ToText IPSetDescriptorType where
     toText = \case
@@ -157,7 +157,7 @@ instance FromText MatchFieldType where
         "query_string" -> pure QueryString
         "uri" -> pure URI
         e -> fromTextError $ "Failure parsing MatchFieldType from value: '" <> e
-           <> "'. Accepted values: BODY, HEADER, METHOD, QUERY_STRING, URI"
+           <> "'. Accepted values: body, header, method, query_string, uri"
 
 instance ToText MatchFieldType where
     toText = \case
@@ -195,7 +195,7 @@ instance FromText PositionalConstraint where
         "exactly" -> pure Exactly
         "starts_with" -> pure StartsWith
         e -> fromTextError $ "Failure parsing PositionalConstraint from value: '" <> e
-           <> "'. Accepted values: CONTAINS, CONTAINS_WORD, ENDS_WITH, EXACTLY, STARTS_WITH"
+           <> "'. Accepted values: contains, contains_word, ends_with, exactly, starts_with"
 
 instance ToText PositionalConstraint where
     toText = \case
@@ -233,7 +233,7 @@ instance FromText PredicateType where
         "sqlinjectionmatch" -> pure SqlInjectionMatch
         "xssmatch" -> pure XSSMatch
         e -> fromTextError $ "Failure parsing PredicateType from value: '" <> e
-           <> "'. Accepted values: ByteMatch, IPMatch, SizeConstraint, SqlInjectionMatch, XssMatch"
+           <> "'. Accepted values: bytematch, ipmatch, sizeconstraint, sqlinjectionmatch, xssmatch"
 
 instance ToText PredicateType where
     toText = \case
@@ -273,7 +273,7 @@ instance FromText TextTransformation where
         "none" -> pure None
         "url_decode" -> pure URLDecode
         e -> fromTextError $ "Failure parsing TextTransformation from value: '" <> e
-           <> "'. Accepted values: CMD_LINE, COMPRESS_WHITE_SPACE, HTML_ENTITY_DECODE, LOWERCASE, NONE, URL_DECODE"
+           <> "'. Accepted values: cmd_line, compress_white_space, html_entity_decode, lowercase, none, url_decode"
 
 instance ToText TextTransformation where
     toText = \case
@@ -308,7 +308,7 @@ instance FromText WafActionType where
         "block" -> pure Block
         "count" -> pure Count
         e -> fromTextError $ "Failure parsing WafActionType from value: '" <> e
-           <> "'. Accepted values: ALLOW, BLOCK, COUNT"
+           <> "'. Accepted values: allow, block, count"
 
 instance ToText WafActionType where
     toText = \case
diff --git a/amazonka-workspaces/gen/Network/AWS/WorkSpaces/Types/Sum.hs b/amazonka-workspaces/gen/Network/AWS/WorkSpaces/Types/Sum.hs
index 2ef7bf6c1fb..e15fc088519 100644
--- a/amazonka-workspaces/gen/Network/AWS/WorkSpaces/Types/Sum.hs
+++ b/amazonka-workspaces/gen/Network/AWS/WorkSpaces/Types/Sum.hs
@@ -31,7 +31,7 @@ instance FromText Compute where
         "standard" -> pure Standard
         "value" -> pure Value
         e -> fromTextError $ "Failure parsing Compute from value: '" <> e
-           <> "'. Accepted values: PERFORMANCE, STANDARD, VALUE"
+           <> "'. Accepted values: performance, standard, value"
 
 instance ToText Compute where
     toText = \case
@@ -64,7 +64,7 @@ instance FromText WorkspaceDirectoryState where
         "registered" -> pure Registered
         "registering" -> pure Registering
         e -> fromTextError $ "Failure parsing WorkspaceDirectoryState from value: '" <> e
-           <> "'. Accepted values: DEREGISTERED, DEREGISTERING, ERROR, REGISTERED, REGISTERING"
+           <> "'. Accepted values: deregistered, deregistering, error, registered, registering"
 
 instance ToText WorkspaceDirectoryState where
     toText = \case
@@ -93,7 +93,7 @@ instance FromText WorkspaceDirectoryType where
         "ad_connector" -> pure AdConnector
         "simple_ad" -> pure SimpleAd
         e -> fromTextError $ "Failure parsing WorkspaceDirectoryType from value: '" <> e
-           <> "'. Accepted values: AD_CONNECTOR, SIMPLE_AD"
+           <> "'. Accepted values: ad_connector, simple_ad"
 
 instance ToText WorkspaceDirectoryType where
     toText = \case
@@ -135,7 +135,7 @@ instance FromText WorkspaceState where
         "terminating" -> pure WSTerminating
         "unhealthy" -> pure WSUnhealthy
         e -> fromTextError $ "Failure parsing WorkspaceState from value: '" <> e
-           <> "'. Accepted values: AVAILABLE, ERROR, IMPAIRED, PENDING, REBOOTING, REBUILDING, SUSPENDED, TERMINATED, TERMINATING, UNHEALTHY"
+           <> "'. Accepted values: available, error, impaired, pending, rebooting, rebuilding, suspended, terminated, terminating, unhealthy"
 
 instance ToText WorkspaceState where
     toText = \case