There are some use cases where it's important to be able to have a clear list of unique module formats (potentially relevant for 0001079, for example). Right now, library users that want to programatically distinguish between unique module formats can start off by taking the file extension returned in libopenmpt metadata, but then some manual fixups need to be applied on top:

• tell the two types of AMF files apart by checking if the format name is "ASYLUM Music Format".
• for the MOD extension, you have to check if the format name is "ChipTracker".

Just taking the format name itself, as it is currently offered by libopenmpt, is not enough, because it may distinguish sub-formats (e.g. for XM there are different format names for each format version 1.01-1.04) in ways that are irrelevant to the library user.

Hence, an additional unique format key that can be easily used programmatically is required. This could be a UUID, or a unique but still human readable variation of the format name (e.g. "amf-asylum" vs "amf-dsmi"). Container formats like MO3 will also need their own unique format key.

For messy formats like the MOD format, it may not be immediately clear where the boundaries of a "unique format" start and end, so it might also be necessary for some library users to distinguish between various sub-formats that are identified by different signatures (e.g. maybe a library user is only interested in M.K. and M!K! MODs but not 8CHN MODs). Maybe a secondary unique format key could solve this.