Does Mp3tag use a particular version of id3 v2 tags - 2.3, 2.4? Is it possible to view which version is currently being used on a particular file (that was tagged by another program)?
Is there any way to view the raw tag names that are used in a file - like TALB, TIT2, TSOP, COMM etc.?
Only v2.3 is written
Keyword: Hex editor ...if you want to find out what's in the tags
BTW it's TPOS
Why only v2.3 with no option to write v2.4?
That would be an answer of 'No'.
No, I meant TSOP. This is "performer sort order" as defined in the v2.4.0 standard. TPOS ("part of set") is defined as being native to both 2.3.0 and 2.4.0, and most often used for the disc number in a multidisc set.
Well, you see, only 2.3.0
Why? I guess 2.3.0 is pretty sufficient.
AFAIK, Florian uses the ID3Lib which only has stable support for ID3v2.3.
Yes, exactly 
I think v2.3 will be fine. I was confused by the id3 specifications and thought that the "native" v2.4 tags could only be used in v2.4 format tags. If they're used in v2.3 tags then my application still recognizes them.
Thanks!