I realize this is archaic. Using Emacs editor with the RCS VC. I can't remember what the RCS 'end-of-comment' keystrokes are. All of my reference manuals are back in my office, that I haven't seen in 10 months.I have tried '.' '..' 'ZZ'. And searching the web brings up some usurping messaging system.
It is always better to have seen your target for yourself, rather than depend upon someone else's description.