Oh where, Oh where has my little rcs gone? - rcs Removed from FreeBSD 12 base

Got a jolt when I tried to "check out" a rcs file this morning.  rcs is Revision Control Systems and is a useful but somewhat outdated way to keep track of file changes. 
https://docs.freebsd.org/44doc/psd/13.rcs/paper.pdf


PROBLEM:
Had upgraded one of my home lab machines to FreeBSD 12.1 from 11.3 and ` co -l filename ` gave an error and there was no co or rcs man page!

ANALYSIS:

rcs was removed from the base system in FreeBSD 12.

https://forums.freebsd.org/threads/rcs-removed-from-base.68737/ '

Did not notice this fact in version 12.0 or 12.1 release notes. Must have been announced sooner, I guess.
https://www.freebsd.org/releases/12.1R/relnotes.html

SOLUTION:

(I need to add either rcs version 5.7-5.7 or 5.9.4_1 from packages on server1).

pkg install -y rcs-5.9.4_1

So all good now!

FUN FACTS:
It was initially release in 1982 by Walter F. Tichy.  https://en.wikipedia.org/wiki/Revision_Control_System as a VCS (Version Control System)

Now replaced by lots of options:  SCCS, svnlite, subversion and may others. "As Internet opened its path through the world, third generation of these tools emerged providing a decentralized version control system, allowing users to keep their revisions in multiple machines, while contributing to the same project. In this generation there are Git, Arch tools (Bazaar, ArX), BitKeeper, Mercurial, and Monotone and many others as the third generation of VCS software tools.^[3] "