The Unique File Identifier Multiple Item View is used to display and edit these items for the current file selection. The Unique File Identifier displayed on the Audio panel is the default item. The default Unique File Identifier is the first item with a description of http://musicbrainz.org.
The table displays the Unique File Identifiers found in the currently selected files.
All editing and manipulation is done via the context menu and is described here.
According to the ID3 specification, this field type is a binary field consisting of at most 64 bytes of data. As the field is typically used to contain a MusicBrainz track identifier, the field is displayed in a string representation. Binary characters are displayed and may be entered as \xx. Where xx is any hexadecimal character (0-9, A-F or a-f).