This information is found in iTunes Cover Flow data files.
Tag ID Tag Name Writable Values / Notes 'data' ImageData no (embedded JPEG or PNG image, depending on ImageType) 'itch' Itch - --> ITC Header Tags 'item' Item - --> ITC Item Tags
Index1 Tag Name Writable Values / Notes 16 DataType no 'artw' = Artwork
Index4 Tag Name Writable Values / Notes 0 LibraryID no 2 TrackID no 4 DataLocation no 'down' = Downloaded Separately
'locl' = Local Music File5 ImageType no 7 ImageWidth no 8 ImageHeight no