This document: - specifies a methodology for the measurement of defined print quality attributes of Digital Postage Marks in the form of two-dimensional bar code symbols on mail-pieces; - defines methods for grading the results of these measurements and deriving an overall symbol quality grade as a guide to estimating the readability of the Digital Postage Marks; - provides guidelines for printing and gives information on possible causes of deviation from high grades to assist users in taking appropriate corrective action; - defines a test procedure for the assessment of printing systems for the production of Digital Postage Marks. These provisions apply to the Digital Postage Mark blocks as they appear on fully produced mail items when remitted to postal operators, including the characteristics resulting from operations other than printing per se that affect their appearance to a mail processing system (covering, inserts into transparent window envelopes, affixed Digital Postage Mark labels). This document does not define the qualification tests or sampling requirements necessary to determine the practical feasibility of any specific read rate. Although this document is not intended for barcodes (other than Digital Postal Marks) which can be printed on mail pieces for item identification or additional services, a similar methodology can be applied.