Mil-Std 129 Change Notice 4: Fewer Barcodes and Labels
Posted by Greg Tsiknas on Tue, Oct 06, 2009
Change Notice 4 of Mil-Std-129P added two linear barcodes and a new two-dimensional symbol (PDF417) to labels commonly required for shipping under defense contracts. While this might be seen as an added burden, Change 4 actually yields some unexpected benefits.
The new barcodes, for CLIN and Shipment Number, were added to the already crowded exterior container label. The location of these two barcodes, side-by-side with the label text, presents a challenge to fit on commonly used 4-inch labels, while staying within the barcode density requirements of Mil-Std-129.
Notice 4 also requires that UIDs and/or serial numbers be included in a new 2D PDF-417 symbol, similar to the one used on MSL labels for several years now. While this change increases the 
amount of data management required for shipments, it also eliminates the need for linear barcodes, because "application of the linear bar codes is not required when the 2D (PDF417) identification symbol is used." [Mil-Std-129P, paragraph 4.4]
Eliminating the linear barcodes on exterior container labels is a great thing, now that those labels could require up to ten linear barcodes: NSN, Contract-Order, CAGE, CLIN, Shipment Number, and up to five serial numbers. Using one PDF417 instead of ten linear barcodes allows a single 4x3-inch label to replace two 6x4-inch labels.
This is critical for RFID-tagged exterior container labels with multiple serial numbers. Two labels are often necessary to accommodate all of the serial number barcodes, but printing those labels on an RFID printer is a problem, since only the first label of the pair would be programmed an RFID. The other would have to printed on different label stock, or have its RFID chip killed so as not to confuse the RFID readers at the receiving activity. This presents problems of its own.
Reliance on a single PDF417 instead of multiple the linear barcodes allows for fewer, and in many cases, smaller labels. The depots benefit as well, because unlike linear barcodes, the data in the 2D symbols is delimited by Data Identifiers. This allows automated systems to quickly read and make sense of all of the encoded data.
Change Notice 4 also allows for use of the 2D symbol in place of linear barcodes regardless of the presence of UIDs and/or serial numbers. This reduces the size of the standard exterior label by half.