sanction, countenance, endorsement, indorsement, warrant, imprimatur (noun)

formal and explicit approval

"a Democrat usually gets the union's endorsement"

imprimatur (Noun)

An official license to publish or print something, especially when censorship applies.

imprimatur (Noun)

Any mark of official approval.

Imprimatur

An imprimatur is, in the proper sense, a declaration authorizing publication of a book. The term is also applied loosely to any mark of approval or endorsement.

Imprimatur

An imprimatur (sometimes abbreviated as impr., from Latin, "let it be printed") is a declaration authorizing publication of a book. The term is also applied loosely to any mark of approval or endorsement. The imprimatur rule in the Roman Catholic Church effectively dates from the dawn of printing, and is first seen in the printing and publishing centres of Germany and Venice; many secular states or cities began to require registration or approval of published works around the same time, and in some countries such restrictions still continue, though the collapse of the Soviet bloc has reduced their number.