Extensions on the end of the names...

Could someone either tell me what the different file names for a single game mean, or point me to a page that tells me? For example, I get (U), (J), and (E) but how about [o1] or [!] though? Thanks!

You don't really have to worry about the various tags, those are only for collectors.The only important tag besides language is [!] which means that it's a proper dump and will work.

That's helpful, thanks. Although, how do I know which one I should download when there isn't one with the [!]?

Please give me an example where such tag isn't present.

Okay. Mike Tyson's Punch-out for the NES has two versions that are (E) and have the [!]. One has (PRG0) and the other has (PRG1). There is no (U) version with a [!].

In that case then choose the ROM without any square bracket tags.

Okay, so for that example, there are two (U) versions that do not have bracket tags. One has (PRG0) and the other has (PRG1) at the end. So you are saying that it doesn't matter which one I choose?

Pretty much, I'll admit though that I have no idea what the PRG tag means, though I doubt it will make much of a difference.Edit: I just posted a topic under tutorials explaining them.

Thanks!