Abstract: Embodiments of the invention generally provide a computer system, method implemented on a computer, and computer readable medium storing instructions for defining an extension taxonomy. The computer system comprises a processor and a memory storing instructions, the instructions being executable to configure the processor to provide a selection module operable to designate a selected portion of a source document, wherein the source document comprises a set of locations and a location map for identifying each location in the set of locations; wherein each location is configured to receive text-based content and wherein the selected portion comprises at least one location in the set of locations.