Using Superimposed and Context Information to Find and Re-find Sub-documents

information (SI) is new information such as annotations created in reference to bits of existing information. SI references existing information using an abstraction called mark. A mark can be activated to see referenced information in its original context. Context information is the set of information obtained using a mark. For example, page number and font characteristics are included in the context information for a selection in a PDF document. Superimposed and context information can make finding and re- finding of sub-documents easier than is possible with the state of the art. For example, search results can embed marks which users can use activate to navigate directly to sub-documents; search results can include context information to potentially reduce the number of click-through operations needed to locate relevant information.