While you can enter yor custom values into the lists for each tag in any order you want, it will always autosort the values alphabeticaly in the tagpanel.
If i wanted them alphabeticaly, i would make the list alphabeticaly!
But when you organize the list in a priority order, with the most used values on top, mp3tag will always destroy your order and shove them down.
For example: For the "language" tag i put
1 English
2 Finnish
3 German
4 Instrumental
5 Norwegian
6 Swedish
7 Icelandic
8+ all other commonly used languages sorted alphabeticaly
Yet in the tag panel, i have to search for these in my collection most common languages, because mp3tag thinks they better be mixed into the lower group.
And the same goes for 7 other tags that i would like to define the order myself.
If you write that string to the language field then you leave the boundaries of the ID3 standard which defines this field as:
"The three byte language field is used to describe the language of the frame's content, according to ISO-639-2."
The proper code for "German" would be "deu" according to that standard.
Yes, this is by design — it's also with track titles, artist names, and other fields when you select multiple files.
I currently have no plans in changing this, although I understand that it would be useful to you.
You're probably aware that you can type the first letters and the field tries to auto-complete. It's not what you've asked for, but I wanted to mention this anyway because it might speed things up a little.
Ok, forgot about the typing, that may help a bit...
PS: Since i kinda omitted it in the first post, i wasnt asking for a complete change of the behavior, more for a little tick box "sort alphabet/numericaly <-> sort by list order" in the user defined list setup menue. Ubiquitously changeing it for all fields including track numbers would be insane.
Yes, I understood it like that. The Tag Panel configuration (including custom values) is already peak complexity for some if not many users, so I'm currently hesitant to add more options there.