SNES. roms, a lot of versions, what to choose?

I see that the SNES roms got a lot of version in them, first are the languages, but there is also like [b1], [f1], etc... in the names.
What does that mean?Thank you !

This page explains ithttp://forum.romulation.net/index.php?topic=1359.0Just try to find the [!] one

Thank you very much.
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I have another question if you dont mind....
I see that i have 2 files with [!], one of them is version 1.0, and the other one is 1.1I know that its always best to have the last version, is it true for this games also?Thank you !

different versions generally mean that the lower version had a game breaking bug which is fixed in the higher version.