Editorial principles: cross-referencing
The turning of cross-references into hotlinks is a valuable part of the enrichment carried out during the preparation of material for EE. This process is a complicated one, however. Whether letters are identified in the source editions by number (e.g. "Letter 12345") or by correspondent + date ("Cowper to John Newton, 19 July 1784"), these identifications are also used in other contexts, so all links have to be checked. In addition, many cross-references are to page numbers or even notes, further complicating the process. These and other problems with identifying cross-references mean that this task is still ongoing.