to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
It is an anonymous, pseudonymous or posthumous work and 50 years have passed since the date of its publication
It is a photographic work, and 25 years have passed since the date of its publication
It is another kind of work, and 50 years have passed since the year of death of the author (or last-surviving author)
It is an "official act of authority" and ineligible for copyright protection; however "literary, artistic, or scientific publications produced by the authorities" are copyrighted by the government