Game file naming conventions

Dear community members,

I can't seem to find a naming convention FAQ anywhere. Please excuse the n00by question, but in addition to the title, year and developer, what is the additional information typically included in a game file name?

I have a few examples:

3d24 (1993)(L.K. Avalon)(pl)[b].atr

Roadwar Europa (1987)(SSI).st
Roadwar Europa (1987)(SSI)[a].st

I'm guessing the [pl] in the first file indicates Polish language? If somebody could provide a link to a key, I'd be like :party:

The list of symbols is attached.

Attachment 55974