The Revision Control System (RCS) manages multiple revisions of files.  RCS
automates the storing, retrieval, logging, identification, and merging of
revisions.  RCS is useful for text that is revised frequently, including source
code, programs, documentation, graphics, papers, and form letters.

This port is gnu rcs 5.7. It is compatible with the rcs that was in FreeBSD
prior to its removal in FreeBSD-10.0. Some ports will not work with changes
made to rcs (e.g. changes to command line syntax) following the rcs 5.7
release.