CIC 2477 Respect for the reputation of persons forbids every attitude and word likely to cause them unjust injury.1 He becomes guilty:
– of rash judgment who, even tacitly, assumes as true, without sufficient foundation, the moral fault of a neighbor;
– of detraction who, without objectively valid reason, discloses another’s faults and failings to persons who did not know them;2
– of calumny who, by remarks contrary to the truth, harms the reputation of others and gives occasion for false judgments concerning them.

1 Cf. CIC, can. 220.
2 Cf. Sir 21:28.