CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 2506–2509

2506 The Christian is not to "be ashamed of testifying to our Lord" (2 Tim 1:8) in deed and word. Martyrdom is the supreme witness given to the truth of the faith.
2507 Respect for the reputation and honor of persons forbids all detraction and calumny in word or attitude.
2508 Lying consists in saying what is false with the intention of deceiving one's neighbor.
2509 An offense committed against the truth requires reparation.