20. The system of claim 17 , wherein the at least one annotation further includes at least one of: a user-provided text, a user-defined attribute, a reference to a URL, a reference to another section of the shared document, and a reference to another data storage.
20. The system of claim 17 , wherein the at least one annotation further includes at least one of: a user-provided text, a user-defined attribute, a reference to a URL, a reference to another section of the shared document, and a reference to another data storage. 21. The system of claim 20 , wherein the at least one annotation further includes at least one of: image data, binary data, audio data, video, and text.