Thanks both. Ohren, yes, I would use TRACK instead of TRACKNUMBER - I am trying to debug a received script that uses TRACKNUMBER.
I just did these tests, using a hex editor to view the WMA's WM/Track and WM/TrackNumber, and using the Tag Panel with TRACKNUMBER added under Options (assuming this panel's Track: maps to TRACK) to make changes and view.
I started with a file with no tag (showing TRACK and TRACKNUMBER blank).
- changing TRACK and clicking Save changes TRACK, WM/Track and WM/TrackNumber
- changing TRACKNUMBER and clicking Save changes Track:, blanks TRACKNUMBER, does not change WM/Track and changes WM/TrackNumber. Note: Track: and WM/Track now fail to accord.
- Clicking Save again changes WM/Track to the value expected at 2)! Further changes shows WM/Track lags by one Save.
(The value in WM/Track is always the value entered/shows in Track: or entered in TRACKNUMBER or shows in WM/Tracknumber, minus 1.)
This certainly suggests that TRACKNUMBER should not be used. I'g guess its availability is unintentional.
Florian, I suggest the Mp3tag docs http://help.mp3tag.de/main_tags.html:
be amended to show that TRACK maps to WM/Track additionally to WM/TrackNumber, and that TRACKNUMBER has undefined behaviour and should not be used.