.m3u playlists and
.m3u8 playlists (UTF-8 encoded, supports international characters in file names).
Playlists can be loaded via File → Load Playlist/Cuesheet....
After loading a playlist, Mp3tag lists its contents in the order they appear in the playlist. Because of internal design decicions, duplicate references to the same file are not listed in Mp3tag’s File List.
To add files to the File List, you can use File → Add directory... or drag and drop individual files from Windows Explorer while holding the Ctrl key down.
You can rearrange the order of files in the File List using drag and drop while holding the Alt key down.
Mp3tag uses the configuration settings at Options → Playlist when saving playlists via File → Playlist (all files) and File → Playlist (selected files).
If you press Shift when running one of these commands, Mp3tag creates a playlist for every different directory.
To use the file name of the loaded playlist, use the playlist-specific placeholders for the configuration of the playlist file name (or just overwrite the existing file).