I've seen the term "PR" used in the context of packages and maybe even development of packages but didn't see any obvious place I could find a definition of what it stands/is for. Phrases like "submit a PR" seem to be used in the context of packages and/or their development.
I guess „pull request“ is what you‘re looking for.
This might be useful
Ah, of course. I was looking in the wrong argot for the definition.