Some sort of referencing should be possible. For TV or movie synopses, the text itself as an implicit reference is obvious and sufficient, for example.
How far do you want to extend this? For computer games, is unreferenced description of characters ok? What about of cheats and secrets? Of songs, is discussion of lyrics ok? What about chord changes? Etc.
The big question: When is an unreferenced text better than no text?
Steve