+.. _picard: https://picard.musicbrainz.org/
+.. _beets: https://beets.io/
+.. _mpd: https://musicpd.org/
+.. _MusicBrainzIDs: https://musicbrainz.org/doc/MusicBrainz_Identifier
+.. _MBIDs: https://musicbrainz.org/doc/MusicBrainz_Identifier
+.. _MusicBrainz: https://musicbrainz.org
+.. _`ID3 tags`: https://en.wikipedia.org/wiki/ID3
+.. _last.fm: https://www.last.fm/