About the Language Code for Comment and Unsynced Lyrics

[tagger]

@LyricsLover

I'm using my own media library who is capable to let me choose "german" or "spanish" Lyrics as one of the search criterias. In combination with other criterias like Genre (i.e. "Hip-Hop", "Hard Rock") or Artist I can listen to music for my current mood

But you are right, I don't know of any known software other then Mp3tag that can also read and select ("filter") this information.
Maybe there are some plugins for other media player software like KODI, PLEX, EMBY?

I see, so you're using your own software. But still, wouldn't it make more sense to use the Language(s) frame (TLAN) instead? (the thing that ohrenkino just talked about)

From the ID3v2 standards:

TLAN
The 'Language(s)' frame should contain the languages of the text or lyrics spoken or sung in the audio. The language is represented with three characters according to ISO-639-2. If more than one language is used in the text their language codes should follow according to their usage.

Also, you can only have one language code for each lyrics entry, but you can have multiple language codes for the Language(s) frame (TLAN), which is pretty useful for songs that contain more than 1 language.