Roman Catechism 31.12

Chapter 31 — Part III: The Decalogue — The Eighth Commandment

Section 12. All Falsehoods In Lawsuits Are Forbidden — This precept then prohibits deceit, lying and perjury on the part of witnesses. The same prohibition extends also to plaintiffs, defendants, promoters, representatives, procurators and advocates; in a word, to all who take any part in lawsuits.