Unique Identification Marking, UID marking, Item Unique Identification or IUID, is a part of the compliance process mandated by the United States Department of Defense. It is a permanent marking method used to give equipment a unique ID. Marking is essential for all equipment with an acquisition cost of over $5,000, equipment which is mission essential, controlled inventory, or serially-controlled. UID-marking is a set of data for assets that is globally unique and unambiguous. The technology used to mark an item is 2D Data Matrix ECC 200 Symbol.

Tangible items are distinguished from one another by the assignment of a unique identifier in the form of a unique data string and encoded in a bar code placed on the item. An item unique identifier is only assigned to a single item and is never reused. Once assigned to an item, the IUID is never changed even if the item is modified or re-engineered. IUID is similar to social security numbering used to distinguish citizens of the United States from one another.

A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths and spacings of parallel lines. These barcodes, now commonly referred to as linear or one-dimensional (1D), can be scanned by special optical scanners.

Barcodes are widely used around the world in many contexts. The difference between variable data printing and traditional printing is the personalization that is involved. Personalization allows a company to identify on a more detailed scale to ensure proper management of products or data.

All industries utilize barcodes, variable data and UIDs in todays market for tracking, asset management and numerous other forms for identification. To name a few are Aerospace, Aircraft, Automotive, Defense, Education, Electronics, Energy, Government, Healthcare, Industrial, Manufacturing, Marine, Sports and Recreation, Technology and Transportation.