Using RDF to Annotate the (Semantic) Web.
Phil Cross, Libby Miller, Sean Palmer · 2001
Collections of annotations need indexes for certain of their properties. When we have a set of created annotations, we want to be able to ask questions concerning these properties such as: agency: "Who said this?"; timing: "is this the most recent annotation about this object?"; the annotated object itself: "What annotations have been made about this object?"; and content: "Which objects which fail this test?". This document examines an approach to creating annotations on the web in two projects, EARL and MedCER-TAIN. Both projects use RDF (Resource Description Framework) to model annotations in a flexible and extensible way, so that these types of questions can easily be asked.