Pinned comment

A channel owner can pin one comment, their own or a viewer's, and it sits above everything else with a pinned label. Only one is allowed. Pinning a new comment replaces the old one, so the slot has to earn its place: a correction, a link that the description buries, or a question that gives the section somewhere to go. Pinning a viewer's comment costs nothing and does more work than pinning your own, because it rewards the person who wrote it and shows anyone scrolling that you read the replies.