It is a photographic work and 25 years have passed since its creation
It is a cinematographic work and 50 years have passed since the date of its creation
It is another type of work and 50 years have passed since the death of the author (or last-surviving author)
It is an anonymous or pseudonymous work and 50 years have passed since the date of its creation
It is one of "laws, decisions of courts or of administrative bodies and official translations thereof" and therefore ineligible for copyright protection.