A Container which is a container of Items, each of which describes a thing which has been played or has been suggested for playing.

is a bit ambivalent whether the Items which a Playlist is a container of are themselves the things which have been played or have been suggested for playing, or if they merely describes them. This ontology takes the latter approach, primarily because it is not clear that all playable things are necessarily themselves Items.

The definition of “play” here presumably means in the sense of recorded media, not in the sense of games.

The Items describing playable things are not themselves given a more specific type by .