It's not clear if the kill utility appeared in version 2 or 3 of UNIX.
Earliest reference of kill in the TUHS archive is v3 AT&T UNIX.
Unfortunately only the source code for the compiler is present for that
release. The v2 archive is missing the manuals & only contains a some of the
In v3 UNIX, the kill utility is documented in category 8, not 1, attached patch
adds this note to the HISTORY section.