Caps for module music formats

[Carlos Rafael Giani]

Hello,

I have been extending the typefind functions to detect more module 
formats, and to give caps more details.
Currently, all of the formats (MOD, XM, S3M, IT, PSM, ...) are labeled 
as "audio/x-mod". However, different module players support different 
sets of formats.
Therefore, it would be better if the caps described the format in more 
detail.

I see three options:

1. Continue using audio/x-mod as the media type, and add another field, 
"mod-type", of type string. This field can then have values like "xm", 
"s3m", "ult" etc.
2. Replace audio/x-mod with audio/x-s3m, audio/x-xm, etc.
3. Replace audio/x-mod with audio/x-mod-s3m, audio/x-mod-xm, etc.

The first one is backwards compatible. However, it lumps different 
formats into one media type. I am not sure if that is okay.
The second one is probably too ambiguous, and not backwards compatible. 
audio/x-mod used to mean "any kind of module format", now it would mean 
"MOD module format". In addition, audio/x-xm could be misunderstood as 
"XM radio".
The third one is not as ambiguous as the second, but probably confuses 
people, especially with "audio/x-mod-mod".

Opinions?