Thanks for that uncle - for those who, like me, have never heard it before:

nihil obstat:

NOUN: 1. Roman Catholic Church ~ An attestation by a church censor that a book contains nothing damaging to faith or morals. 2. Official approval, especially of an artistic work.

ETYMOLOGY: Latin, nothing hinders : nihil, nothing + obstat, third person sing. present tense of obst re, to hinder.