US Patent 8706685 Organizing collaborative annotations

Organizing collaborative annotations of digital items is described. In a particular embodiment, a server system receives a filter request from a client device to filter a plurality of annotations according to criteria included in the filter request. The plurality of annotations is stored at an annotations database coupled to the server system. The server system sends filter results to the client device based upon annotations matching the criteria of the filter request. The annotations may be filtered based on tags associated with respective annotations, where the tags categorize the respective annotations.