Packages with the rcs use flag

app-misc / gramps : Genealogical Research and Analysis Management Programming System

  • Adds support for family tree archives via dev-vcs/rcs

app-office / lyx : WYSIWYM frontend for LaTeX, DocBook, etc.

  • Add support for revision control via dev-vcs/rcs

www-apps / webdavcgi : A Perl CGI for accessing and sharing files, or calendar/addressbooks via WebDAV.

  • Adds support for a revision controlled backend with RCS (dev-vcs/rcs)