20. The computer system of claim 19, wherein the requested document is a digital document having fixed text content and fixed structure defined by descriptive markup defining a plurality of hierarchical elements providing an indication of structure of the digital document.
20. The computer system of claim 19, wherein the requested document is a digital document having fixed text content and fixed structure defined by descriptive markup defining a plurality of hierarchical elements providing an indication of structure of the digital document. 21. The computer system of claim 20, wherein the data processing component includes means for transforming the selected portion of the requested document according to the structure of the requested document.