It is an anonymous work or pseudonymous work and 70 years have passed since the date of its creation
It is another kind of work, and 70 years have passed since the year of death of the author (or last-surviving author)
It is an "expressions of traditional folklore and art" or "political speeches, speeches delivered in the court"
It is one of "official documents, legal acts, treaties and the official translations thereof, state emblems and signs (flags, coats of arms, medals, monetary signs)"