Backbiting is not limited to spreading falsehood. Mentioning an absent person’s fault or private matter in a way the person would dislike may be backbiting even when the information is true. A false accusation adds a different and serious wrong.
Example 1: People mock an absent friend’s clothing, manner, or personal weakness.
Example 2: A group message circulates someone’s fault to humiliate them.
The key principle: A person’s dignity deserves protection even when they are absent. The fact that something is true does not automatically make it appropriate to repeat everywhere. Special cases involving necessary, legitimate disclosure require separate detailed treatment.