imprimatur(n = noun.communication) countenance, endorsement, indorsement, sanction, warrant - formal and explicit approval; "a Democrat usually gets the union's endorsement"
is a kind of approval, commendation
has particulars: o.k., ok, okay, okeh, okey, visa, nihil obstat

1.  A license to print or publish a book, paper, etc.; also, in countries subjected to the censorship of the press, approval of that which is published. [1913 Webster]

2.  Permission granted from a designated eccliastical authority to publish a book or other document; -- required by church law for Catholics, especially ecclesiastics, who wish to publish. [PJC]

3.  Official approval for some proposed activity; as, a contract this large needs the imprimatur of the legal department. [PJC]

imprimatur, n.
1 RC Ch. an official licence to print (an ecclesiastical or religious book etc.).
2 official approval.

Etymology:
L, = let it be printed