See related thread at the Unix Heritage Society mailing list: <a href="https://www.tuhs.org/pipermail/tuhs/2024-December/031185.html" rel="nofollow">https://www.tuhs.org/pipermail/tuhs/2024-December/031185.htm...</a>
This not about some random source control system, but rather about original product called SCCS (predecessor to RCS, CVS, SVN, etc...), the one of the first version control systems made 50 years ago. This is a retrospective by original author.