Respect for the reputation of persons forbids every attitude and word likely to cause them unjust injury. 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;
- of calumny who, by remarks contrary to the truth, harms the reputation of others and gives occasion for false judgments concerning them.
Source: Catechism of the Catholic Church (Vatican.va)