Thank you for your continuous work on Mp3Tag. I have found some some minor issues in regards to MusicBrainz tags so I am letting you know.
The first one is regarding the tag ACOUSTID_FINGERPRINT. According to your post in Add mappings for more MusicBrainz tags - #12 by Florian it should be present in Extended tags alongside ACOUSTID_ID, however only the latter one is there. I have found my old report in Two issues with Extended Tags - #7 by Florian where I have encountered a bug with two ACOUSTID_ID fields where you have chosen to remove the duplicate one. I had a suspicion that the duplicate ACOUSTID_ID was actually supposed to be the ACOUSTID_FINGERPRINT, however I probably didn't make myself clear enough when reporting it at the time. Could you please take a look and check if it should be added as well?
The second issue is regarding the tag mapping. I have checked all of MusicBrainz tags for ID3 and Vorbis and I have found out that 3 tags do not match the Vorbis mapping according to MusicBrainz documentation in Appendix B: Tag Mapping — MusicBrainz Picard v2.6 documentation. The tags are MUSICBRAINZ_ALBUMSTATUS, MUSICBRAINZ_ALBUMTYPE and MUSICBRAINZ_ALBUMRELEASECOUNTRY. According to the source mentioned, they should be mapped to RELEASESTATUS, RELEASETYPE and RELEASECOUNTRY respectively.
What is interesting about these 3 tags is that they aren't really identifiers like the other MusicBrainz tags (e.g. with values such as 81cba7a1-222e-4901-b5c8-134ddd4e85aa), but instead they are just like other tags (e.g. with values such as official, single and US).
Here is a summary of how it looks now and how it should look:
|Mp3Tag||MusicBrainz ID3||MusicBrainz Vorbis|
|MUSICBRAINZ_ALBUMSTATUS||TXXX:MusicBrainz Album Status||MUSICBRAINZ_ALBUMSTATUS -> RELEASESTATUS|
|MUSICBRAINZ_ALBUMTYPE||TXXX:MusicBrainz Album Type||MUSICBRAINZ_ALBUMTYPE -> RELEASETYPE|
|MUSICBRAINZ_ALBUMRELEASECOUNTRY||TXXX:MusicBrainz Album Release Country||MUSICBRAINZ_ALBUMRELEASECOUNTRY -> RELEASECOUNTRY|
In the meantime I have remapped the fields using the custom mappings but perhaps you'd like to change them for everyone by default so that's why I have decided to report this to you as well. If this isn't an oversight but there is a reason why these 3 tags are mapped like this, please let me know. Also, I have not checked other formats except ID3 and Vorbis so I am not sure how are other formats mapped.
Thank you for taking a look at it, it is very much appreciated!