Mp3tag displays tag fields either directly with their corresponding name from the files (e.g., for files with APEv2 tags like Musepack or VorbisComments like OGG and FLAC) or uses a fixed mapping from format-specific names to human-readable names (e.g., for ID3v2 identifiers or MP4 atoms). For example, the ID3v2 field TPE1 is mapped to ARTIST in Mp3tag.
You can customize mappings from Mp3tag's internal field name to
a user-defined field name in case you need to make field names
consistent across different types of tags (e.g., YEAR in ID3v2 and
DATE in FLAC) via 'Options > Tags > Mapping'. There you can
create mappings for a specific tag type (APEv2, ID3v2, MP4, VorbisComment or WMA)
and provide a Source name (Mp3tag's name) and a Target name (your
preferred field name).
After reading tags from files, Mp3tag translates all source field names to their respective target (and vice-versa when writing tags).
Imagine you want to use one field name YEAR for the release year regardless of whether you are using MP3s (which already have YEAR as Mp3tag's name for release year) or FLACs (which have DATE). To create this unique field that can be used accross the different formats, you need to create a new mapping for VorbisComment (since FLAC files have VorbisComments) and provide DATE as Source (it is the name displayed in Mp3tag so far) and YEAR as Target (this is the field name you like to use). When you now reload the files, you will notice that instead of DATE the field is now displayed as YEAR and you can use this in format strings and everywhere else without differentiating between tag formats.
»But what happens when I save the tags?« you ask. Mp3tag then applies the mapping in the reverse direction. So any field that uses the name provided as Target gets translated to the corresponding Source field name. It's also possible to map multiple Source fields to one Target (e.g., DATE and RELEASE to YEAR). Please note that this implies that all Source fields are written on tag updates. Mapping one Source field to multiple Target fields is not supported.
Made with love in Dresden. Copyright © 1999-2017 Florian Heidenreich. All rights reserved.