[TUHS] Name of UNIX Program Generic

[Thalia Archibald via TUHS]

What was the common shorthand for UNIX Program Generic Issue 3?
Generic 3.0, as Pirzada refers to it [0]?
"UNIX PG-1C300 Issue 3”, as it identifies itself in /usr/sys/lib1?
PG3, as chosen for our recent release of the tapes?

Why was UNIX Program Generic called something so, well, generic?
Is it part of a larger naming scheme?

Thalia

[0]: https://www.tuhs.org/Archive/Documentation/Theses/Shamim_Sharfuddin_Pirzada-1988-PhD-Thesis.pdf