/ @ [ ] Document must contain exactly one tracklist. Tracklist: Tracklist must contain at least one track. : description must mention the described topic Elements of type <name /> should have a unique 'id' attribute An element of type should have an 'album_ref' attribute that should contain a unique identifier. An element of type should have an interpret_ref attribute that should contain a unique identifier. An element of type should have a company_ref attribute that should contain a unique identifier. A band must have more than one person, use soloartist instead. A band must have exactly one name.