Note these field names are meta metadata names. If our audio files are Flac or Ogg format then the name maps directly to a fieldname with the same value, but if we are using other formats such as Wav then these fieldnames may map to an underlying field for that format with a different name. For example Conductor maps to CONDUCTOR for a flac file but to the ID3 frame TPE3 in Wav using the ID3v24 tagging format.
You can see the list of MinimServer field mappings here
And SongKong mappings here
When you would like to use a field added by SongKong or some other field displayed in your music player or tagger that the display name may not be the same as the actual name so in a way there are actually two levels of meta metadata fieldnames.
For example if we take FLAC, the easiest format to deal with then SongKong fieldname Conductor maps to CONDUCTOR, and MinimServer maps this to CONDUCTOR so this is simple and no problem.
But if we take the SongKong fieldname Album Artists this is actually stored by SongKong in Flac as ALBUM_ARTISTS and therefore you need to specify ALBUM_ARTISTS in the MiniminServer configuration
Typically SongKong replaces spaces in the display name with underscores and this is the only difference but not always, for example for Flac format MusicBrainz Release Id is stored as MUSICBRAINZ_ALBUMID. Then for historical reasons and compatibility with other applications (such as MusicBrainz Picard) we can not always use the same value for all audio formats. So for ID3 (as used by Wav and Mp3) the MusicBrainz Release Id field is stored in TXXX frame as MusicBrainz Album Id
So this means if we have music files in multiple formats we may have to use MinimServers tag aliasing feature to treat multiple different fieldnames from different formats the same
For example if we wanted to index the MusicBrainz Release Id for Flac and Mp3 we would add the following:
aliasTags:MusicBrainz_albumId:MusicBrainz Album Id indexTags:MusicBrainz Album Id
The first line ensures that any fieldnames called MusicBrainz_albumId (from Flac) are treated the same as MusicBrainz Album Id (from ID3) . The second line adds MusicBrainz Album Id as an index field
It is worth noting that MinimServer is case-insensitive for these fields so it doesn’t matter if you use mixed case or upper case. For example although the underlying tagging format may treat MusicBrainz_albumId and MUSICBRAINZ_ALBUMID as different fields MinimServer will read both and treat them as the same field.