URL description (MP3/WWW field/WXXX frame) is forced to uppercase

[kanda]

According to ID3 v2.3, v2.4 (4.3.2. User defined URL link frame),
the URL description is “a text string according to encoding”,
which means lowercase letters are fully legitimate.

However, Mp3tag’s Extended Tags dialog forces URL description
to uppercase for several alphabets (Latin, Cyrillic, and possibly others):

It also uppercases existing lowercase descriptions when showing WXXX frames:

what is misleading.

mp3tag is concurrent development: v3.32c, Nov 19 2025 12:36:00 (64-bit)
This is a followup to the [Can’t add more than one WWW tag info WMA file]

[ohrenkino]

By default any field name is upper case only.
If you need a different case, then set the desired case in the file userfields.ini.
See also here:

Copying data from extended tag (catalognumber) to custom tag (CATALOG)

Thank you - but is there a way to create the custom tag called Catalog to use in the action? I can for example in SAM Broadcaster edit the tag and save it (on an individual file) then see it in Music Brainz but cannot see that tag in MP3TAG or select it from the dropdown when creating the action. (I have found CATALOG does not work in SAM Broadcaster either, it has to be Catalog for it to pick it up) Many thanks.

[kanda]

@ohrenkino

By default any field name is upper case only

The metadata “WWW xxxxx…” (and even “WWWxxxx…)” above look like field names, but they are not.

“WIKIPADIA”, “SHAZAM ALBUM” and other descriptions from the image above are parts of user data.

This is a Mp3tag UI design decision, specific to ID3v2 WXXX frame :

@Florian

You can try WWW DESCRIPTION as field name via the extended tag dialog. It then uses the DESCRIPTION part as description for the WXXX frame

[Florian]

As I've explained before, this is how Mp3tag works wrt. to the WWW field for ID3v2. It's a tradeoff I made to support the description part of the field without adding format-specific UI.

I don't plan to change the behaviour and I'm moving this to Bug Reports > No Bugs