I appreciate the idea, but the comma just looks horrible to me as part of a filename. I can imagine someone unfamiliar with the naming scheme to get confused.

I'd prefer to use underscore (when writing BASH scripts, I name all my local variables starting with underscore), but a simple two or three letter prefix would also work. I don't like the idea of a punctuation prefix as punctuation usually has a specific meaning somewhere and including it as the first character in a filename looks wrong. (e.g. Comma is typically used as a list separator and it's a bit of cognitive dissonance to see it not used in that context)