Item Unique Identification is first and foremost about serialized traceability by directly marking items/parts/products with machine readable data. It is best to think of the IUID mark as a barcoded part-mark. But that can be misleading since the DoD concluded early-on that over 80% of all IUID ‘marks’ are more appropriately destined to be incorporated into data-plates, name-plates, asset tags and yes – even labels. The requirements for IUID can originate in contracts either explicitly or indirectly via DFARs clauses and even via flow-downs and drawings. Failure to comply with IUID can be costly and negatively impact future contracting opportunities. Missed IUID compliance will lead to outright rejections and increased costs for returns and rework.

This guide will build your awareness of the scope of requirements for IUID including barcoding, label materials, protection, and processing. When you are finished you’ll have a better idea of whether you’re ready to begin making your own IUID tags or if you’re better off having EasySoft produce them.

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Requirements In-Detail


Historically Mil-Std-130 has been the definitive authority for permanent part marking. It covers part markings for both Human Readable Information (HRI) and Machine Readable Information (MRI). If you see Mil-Std-130 as a requirement in a contract, it may not mean that IUID is a requirement. It may simply mean that the part needs to be marked with Human Readable Data. When IUID is the specific requirement, it most often will be spelled out using DFARS clause 252.211-7007 and DFARS Final Rule 252.211-7007.


One of the critical requirements is that a part mark should last the useful life of the part. The reasoning makes sense. When an item is at the end of its useful life the part mark will make reordering much easier. The other reason for permanency is encountered with items that are reworked or repaired in the field. In many cases the correct repair or refurbishment is impossible without knowing exactly the part number or serial number of the item to be worked on. The impact of this requirement means that any tag or label that is affixed to an item must be capable of withstanding everything the part may reasonably endure in its lifetime such as temperature extremes, ultraviolet light, humidity, salt-spray, chemicals, abrasion, and impacts. IUID tags are in-effect engineered-products that must therefore be specified to match these conditions. Any contractor with IUID requirements should have a specification of the materials, layout, and formatting of the data.


The most critical feature of IUID markings is the DataMatrix barcode. Organizations involved in IUID production must be equipped with specialized verification equipment. Like all barcodes, there are international standards which help define how the contrasting elements of a Datamatrix barcode are constructed from a dimensional standpoint and schematic standpoint. Additionally the data within the barcode needs to follow additional standards for data formatting. Verification and testing must support the production of the UID Tags. It is not enough to successfully scan the data using a smartphone, the UID barcode verifier supports both barcode print quality and data formatting criteria and yes this equipment is expensive.


Depending on the performance requirements there may be one or more candidate materials. Practically speaking, most organizations will take a least-cost approach that delivers against the minimal requirements. Generally speaking, the least costly type of UID tags are made using industrial thermal transfer printers. On the other hand, photo-anodic processes and laser processes can be fairly expensive. Like all things in life, higher performance comes at a price.

When the item spends its life indoors in a lab or office environment a thermal transfer material may be all that is necessary such as our polyester UID labels.

When items are expected to spend up to 10 years outside, a more durable label is required such as our DuraBlack aluminum UID tags.

For some of the most demanding applications you may want to consider 304 Stainless UID Nameplates or 316 Stainless Tags.

Finally, Tesa Secure PV6-6973 is a polyacrylic material that when laser engraved is durable enough for many chemical scenarios and can last outdoors for up to 7 years.


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. By design, the Datamatrix barcode can be produced in very small sizes. When size or function limits the available real-estate for IUID markings, the contractor is allowed to simply mark the item with the Datamatrix barcode alone. Typically we’re talking about ½ inch square or less. Otherwise the contractor is requested to mark both MRI and HRI as part of the marking/label/tag. Once you get more than about 1 inch wide by ½ inch high this MRI + HRI mark is feasible. If you have the ability or desire (or a drawing that demands it) additional linear barcodes that repeat the HRI data may also be part of the design. In the spirit of “less is more” it is our suggestion to skip the use of linear barcodes on IUID tags if you can.

Item Unique Identification is premised on the requirement that any IUID serial number must be globally unique. There are multiple ways to generate and format the IUID data. The IUID’s uniqueness is achieved by pairing, or concatenating, the Serial Number with an Enterprise Identifier (usually in the form of a CAGE Code). This first type is known as Construct #1. To allow for improved and more explicit data management, the uniqueness of the IUID may be achieved by concatenating the Enterprise Identifier with a Part Number and a Serial Number. This second type is known as Construct #2.

Inside the barcode these Construct #1 or Construct #2 data are able to be parsed out based on how they associated, or formatted, with variables known as Data Identifiers. There are two major dialects of formatting known as FORMAT 06, and FORMAT 12. If you have the ability or desire (or a drawing that demands it) you may use FORMAT 12, but we would recommend using the more common FOMRAT 06. Whichever formatting you use, you should try to consistently use the same formatting across your product lines.

IUID Checklist

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You need to be on the lookout for mention of Mil-Std-130, explicit UID or IUID clauses. There are also DFARS clauses to be on the lookout for such as 52.211.xxxx and 52.211.xxxx. If you are in possession of government property there may also be UID requirements which show up in these clauses 52.211.xxxx and 52.211.xxxx.

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The UID tag must be readable at the “end-of-life” which means the barcode should survive in machine-readable condition after prolonged exposure to all expected environmental scenarios. Ultra-violet light, water, humidity, chemical and solvent exposure, abrasion, and temperature extremes must be taken into consideration. These scenarios have the potential to force increasingly costly material and processing decisions.

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Once your product design engineering team has concluded which materials and processing is required, these should be documented in the product documentation such as bills-of-materials and drawing packages.

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Product engineering, warranty management, product sales and quality departments will probably lean on an in-house expert. If that expertise is not in-house it may need to be developed. Even if a manufacturer has the means to mark the right materials, they may lack the expertise, software, and barcode verification and inspection equipment to produce the tags in-house. Of course EasySoft can does have these capabilities and expertise.


Is a UID the same as a UII?
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Unique Item Identification can be used to establish and track uniqueness across all types of things including vehicles, electronic devices, equipment, and even people. In some cases UID may refer to a system of tracking. In our case we are talking about the goods involved. And in practice as a government contractor you are usually focused on the physical tag that is applied for tracking purposes. The UID may be comprised of data elements that together establish uniqueness such as Cage Code and Part Number and Serial Number. Within the barcode, these are actaully 3 seperate pieces of information. But within information systems and tracking systems they may be combined into a single string that establishes a concatenated Unique Item Identifier or UII. When you are asked for a UII you are needing to provide a single string which usually begins with the letter D.

Does a contract referencing Mil Std 130 mean that it requires UID?
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By itself Mil-Std-130 means that the part must be permanently marked at a minimum with Human Readable information such as CAGE Code and Part Number. When IUID is required, Mil-Std-130 is invoked for both Human Readable and Machine Readable standards.

What CAGE Code should I use for the enterprise identifier, the product manufacturer or the reseller of the product?
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If no UID exists for the product, only the Contract Awardee can assign a UID string using its own CAGE Code. Do not use another CAGE Code unless you are contractually performing work on behalf of another CAGE Code bearing entity which is authorizing you to use its CAGE Code.

How do I determine what material to select when ordering a UID tag?
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The UID tag should be treated like a product nameplate. It should last expected life of the product and still be machine readable. It is this machine readable requirement which means that the material performance characteristics of the UID material are critical It is helpful to consult with your UID provider, but ultimately it is your responsibility to employ the right materials.

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