Use Cases/Annotations of annotations as a discourse

A series of annotations form a line of discourse. For example, person A has annotated some photograph with a description "...World War I damage to a castle tower..." Person B comes along and annotates the first annotation with a response "...not damage from World War I, tower damaged in the Palatinate War in 1689." While it is obvious that person B is annotating Annotation 1, it seems to me that it is also the case that the target of Annotation 1 is also a target of Annotation 2 and so the actual target is a composite of the photograph and Annotation 1.

Not only does the model need to support this kind of functionality, but we as a group need to come up with some foundational best practices for cases like these, which are likely to be common for some annotation clients. In this case it's simpler to just target Annotation 1 but, it is more correct to target the composite of the photograph and the Body of Annotation 1, because that is what Annotation 2 is truly about.

Contributed by Jacob Jett