“1.9” refers to the original retail packaging of Final Doom for DOS
and Windows 95, and is by far the most common version of the game
available.  It has been included with various re-releases such as the
Doom Collector's Edition and the Steam version.

“anthology” refers to the less common release that first appeared in
some (but not all!) printings of the id Anthology set.  It includes an
official fix for the MAP31 yellow key.  This version has also appeared
on the Macintosh Final Doom release and the GOG.com release.

*-to-pwad.vcdiff is special.  They will create a PWAD version of TNT
Evilution, containing only the levels and demo lumps.  It may be used
in conjunction with Freedoom to see what the levels turn out like with
different resources.  For demo compatibility, you can come in from
either 1.9 or anthology and it creates a PWAD with those specific
versions of the levels.

If unsure about which version you have, refer to these sha1 hashes:
9fbc66aedef7fe3bae0986cdb9323d2b8db4c9d3  tnt_1.9.wad
4a65c8b960225505187c36040b41a40b152f8f3e  tnt_anthology.wad
5066833da047117241cdda05a708b009eb266c91  tnt_psn_eur.wad
139e26d801a64b404b8d898defca10227a61867b  tnt_psn_usa.wad
503271390606ebded04a2cfaa1a4e249c0313a9d  tnt_unity_1.0.wad
ca0f0495a6c2813b49620202774c56560d6d7621  tnt_unity_1.3.wad
9820e2a3035f0cdd87f69a7d57c59a7a267c9409  tnt_kex.wad