https://musicbrainz.org/doc/Style/Titles says:

"Titles and subtitles of mixes/versions are formatted according to the appropriate language's guidelines; the other parts of this extra information should be in lower case except for words that would normally be capitalised in the language."
Since this doesn't seem to be clearly lifted in https://musicbrainz.org/doc/Style/Language/German there's the strange situation that it's not clear whether it's allowed to write German ETI in normal German capitalisation.

Perhaps a small note can be added on that