12. The process as set forth in claim 11, wherein the element descriptor for an element includes an indication of the location of the text content, for each element containing text content, and, for each element, the type name of the element.
11. A process for generating a digital information product comprising computer data signals defining a representation of a digital document, the digital document having descriptive markup defining a plurality of hierarchical elements, wherein each element except a root element has an ancestor element and wherein each element has type name and may have a child element, a left sibling element, a right sibling element, and wherein at least one element contains text content, the process comprising: parsing the document to provide a sequence of element events in response to detection of elements and text events in response to detection of text content; assigning, in response to an element event, a unique element identifier to each element event; constructing the type name for each element from the descriptive markup defining the element; and generating an element descriptor for each element, addressable by the unique element identifier assigned to the element, wherein the element descriptor stores an indication of any parent element, any first child element, and any left sibling element for the element, and encoding each element descriptor in a computer data signal.