rcs(1) on Linux
The text f0f787fb1ac4, as Debian 9 (Stretch) shipped it.
change RCS file attributes
Flags it lists
-
-A -
-I -
-L -
-M -
-N -
-T -
-U -
-V -
-a -
-b -
-c -
-e -
-i -
-k -
-l -
-m -
-n -
-o -
-q -
-sstate -
-t -
-t-string -
-u -
-x -
-z