From DoomWiki.org

WCF, or Wadgame Configuration Files, are used by WadAuthor to define general parameters of the game for which wadfiles are intended. A WCF file contains information for all the Thing, Linedef and Sector types required for mapping. WadAuthor is distributed with WCF files for Doom, Doom II, Heretic and Hexen. There are also WCF files for source ports, allowing WadAuthor to make use of their new features.