Council of Trent: Session XXIII, Reformation, Chapter IX

CHAPTER IX. A bishop ordaining one of his own household, shall at once and really confer upon him a benefice.

A bishop may not ordain one of his household, who is not his subject, unless he has lived with him for the space of three years; and he shall really, and without fraud of any kind, at once confer on him a benefice; any custom, even though immemorial, to the contrary notwithstanding.

Translation: J. Waterworth, The Canons and Decrees of the Council of Trent (1848), Hanover Historical Texts Project transcription (1995).