If you expand the definition of "comments" to encompass all of these — and that's an appropriate expansion in this case, since I expect to use the same code behind the scenes — I see the following general types of comments as applicable to FromThePage documents:
- Annotations: Pure annotations are comments left by users for the community of scribes and the general public. They don't have "state", and they don't disappear unless they're removed by their author or a work owner. Depending on configuration, they might appear in printed copies.
- Review Requests: These are requests from one scribe to another to proofread, double-check transcriptions, review illegible tags, or identify subjects. Unlike annotations, these have state, in that another scribe can mark a request as completed.
- Problem Reports: These range from scribes reporting out-of-focus images to readers reporting profane content and vandalism. These also have state, much like review requests. Unlike review requests, they have a more specific target — only the work owner can correct an image, and only an admin can ban a vandal.