This page describes comments on anything except wall posts.
This seemingly complicated mechanism instead of the regular inReplyTo is needed so that:
- There's a single source of truth about comments
- The object owner gets to enforce their privacy settings and blocks
- The object owner gets to delete unwanted comments
Each comment is a Note which is part of a publicly-appendable collection as per FEP-400e. The collection depends on the type of the comment's parent object:
- For photos, all comments on all photos in a given album reside in that album's collection, whose ID is specified as
sm:commentsin the album object - For board topics, the topic itself is the collection that contains its comments