  I noticed there are three distinctions: *Physical single releases (ex: Spring of a Twenty Year Old - iTunes) *Digital single releases (ex: Nagging - iTunes) *Promoted single releases (ex: Boo from Growing Up, where a MV was created and she promoted the song actively on music shows)  I think this can be done in anyway – there seems to be no standard. Here are examples from other artists: *Wonder Girls: Single albums (both digital and physical) and promoted single releases displayed separately *Super Junior: Divide into single albums and digital single albums *Sunny Hill: Divide into single albums and digital singles *Korean IU discography: Only single albums (both digital and physical) are listed. Promoted tracks from an album are mentioned on the album description, ignoring the charting details.   