This graphic illustrates an Electronic Return Document Location Number (DLN) and a Form 8453 Document Location Number (DLN) with explanation labels for both as follows:digits 1 and 2 represent the Filing Location Codedigit 3 represents the Tax Classdigits 4 and 5 represent the Document Codedigits 6, 7 and 8 represent the Julian Datedigits 9, 10 and 11 represent the Blockdigits 12 and 13 represent the Serial Number anddigit 14 represents the List Year.