The military has definitions of packaging that help in understanding how to mark a complete shipment. The standard defines multiple layers of packaging. It starts with the item being packed. That item’s first level of packaging is called the Unit Pack. On the other end of the spectrum, a shipment handling unit is defined as an Exterior Container. Shipments can be comprised of multiple Exterior Containers. If you are shipping Parcels, each carton with a shipping address label is considered an Exterior. If you are shipping Pallets, each pallet is considered an Exterior Container. More layer definitions exist within the standard.
There are three main label types to be considered in Mil-Std-129 – the Military Shipping Label (or MSL), the Container Markings (both HRI and MRI) and Radio Frequency Identification Tags (RFID). Mil-Std-129 by itself doesn’t mean RFID is required. There are DFARs Clause in the contract, bid-package, or master solicitation which govern whether RFID is required. All three of these labels are found on Exterior Containers. Inner containers have their own Container Markings – like the Unit Pack with its Unit PACK label. Inner containers, however, do not require RFID or MSL labels. There are variations on most label types depending on the contents of the package and terms of the contract. Lot numbers, expiration dates, shelf-life and warranty data may be required based on the contract terms. Serialization is one of the more demanding scenarios for package labeling as each layer’s package labels need to repeat the serial data for all items within. Item Unique Identification requirements add a layer of complexity to serial identification.!
Each layer of packaging in a shipment has distinct marking requirements. There are two types of marking. Human Readable Information (HRI) is comprised of text and numbers. Machine Readable Information (MRI) is data that can be read by a machine – namely barcodes.
Mil-Std-129 gets as detailed as defining how text and human readable information is formatted and ordered on the label. The standard considers the type of fonts, and how small or large the text should be.
Although barcodes may look straight forward – their construction must follow several international standards that are referenced by Mil-Std-129. When these standards are followed, the resulting barcodes will be successfully read by any barcode scanning hardware. When these standards are not followed the barcodes may not read in the field – which may result in rejected shipments. Since barcodes are produced by a system of software working with printers, blank label stocks, and contrasting inks and transfer materials any one of these system components can lead to failure.
While Mil-Std-129 provides for markings to be stenciled, the vast majority of markings will be applied via adhesive labels that have been printed. There are a wide variety of label stocks and adhesives in the marketplace, but the DoD has found the need to specify the performance criteria for Mil-Std-129 labels. These criteria are partially defined within the standard, but are more explicitly defined in Mil-Prf-61002. Paper labels are ok, but labels on Exterior Containers should be over-laminated.