Purchased MPEG-4 tracks from Apple may contain various metadata items which are non standard. Most of these items end up in the Unhandled section. The following store items will be available as UDTIs when they are encountered:
- Apple Store Account Type
- a numeric value. This can be iTunes or supposedly AOL ... which we've never seen.
- Apple Store Artist ID
- a numeric value. Some others refer to this as the Album-Title ID, however as the same values are often returned for this item and the composer ID, we believe that it represents an artist.
- Apple Store Catalog ID
- a numeric value
- Apple Store Composer ID
- a numeric value
- Apple Store Genre ID
- displayed as: # (symbolic genre if available)
- Apple Store Flavour
- a text string displaying information about an item's encoding or representation
- Apple Store Playlist ID
- a numeric value. This more than likely represents the album.
With the exception of Apple Store Flavour, these values are all stored as binary integers. If you manually edit the fields, only a leading integer is retained when the file is saved.