Chapter 45: Why Symbologies Die - A Summary | The history of barcodes is not merely a story of technological evolution; it is a graveyard of symbologies. For every Code 128 or QR Code that achieved global ubiquity, dozens of other barcode types have faded into obscurity. Understanding why these symbologies die is as important as understanding why others succeed. The causes of death are remarkably consistent across the decades, and they can be distilled into six primary factors: Low data density, Lack of error correction, Proprietary nature, Poor print contrast, The emergence of a superior standard, and High scanner cost. This chapter examines each of these factors in detail, using the story of Code 39 as a lens through which to view the rise and potential decline of a symbology, illustrating how the interplay of these factors determines the fate of barcode technologies across various industries. | The six factors that lead to the death of a barcode symbology are interrelated and often compound one another. A proprietary symbology may require expensive scanners, limiting adoption. A lack of error correction may lead to misreads, which in turn reduces trust in the technology. A low data density may necessitate large labels, which are impractical for small items. The emergence of a superior standard provides an alternative that resolves many of these issues, leading to the gradual abandonment of the older symbology. This chapter explores this process through a detailed examination of Code 39, a symbology that, despite its age and limitations, continues to serve specific niches while being displaced in others. | 
| The Case of Code 39 | To understand why symbologies die, one must first understand the technical and historical context of the survivors. Code 39, developed by Dr. David Allais and Ray Stevens of Intermec in 1974, was the first barcode symbology to support both letters and numbers, making it a revolutionary tool at the time of its introduction. Known by several names, including Alpha39, Code 3 of 9, and USD-3, it was designed for non-retail applications that required more than just numeric data. Its specification defines a variable-length, discrete barcode that encodes 43 characters: uppercase letters A through Z, digits 0 through 9, and several special characters like the dash, period, space, dollar sign, slash, plus sign, and percent symbol. An additional asterisk (*) character serves as both the start and stop delimiter. | The structure of Code 39 is both its strength and its primary weakness. Each character is composed of nine elements: five bars and four spaces, with three of these nine elements being wide and six being narrow. This 'two-out-of-five' coding scheme is what gives Code 39 its name (originally 39 characters, later expanded to 43). The width ratio between narrow and wide elements is not critical and can range from 1:2 to 1:3, making it somewhat tolerant of variations in printing quality. However, this very characteristic contributes to its low data density. | One of the most notable features of Code 39 is that it does not contain a mandatory check digit. Instead, it is considered 'self-checking,' meaning that a single erroneously interpreted bar cannot generate another valid character. This self-checking property is a form of rudimentary error detection, but it does not provide the robust error correction or verification that a dedicated check digit offers. The absence of a check digit simplifies integration, as it allows for the generation of barcodes by simply adding a Code 39 font to a printer and printing the raw data. This ease of implementation was a significant factor in its early and widespread adoption. | However, this simplicity comes at a cost. The most serious drawback of Code 39 is its low data density. It requires more space to encode data than more modern symbologies like Code 128. For example, a Code 39 label with 10 data characters and an element width of 20 mils would have a total length of approximately 3.64 inches, whereas an equivalent Code 128 label would be only 3.30 inches, and a Code 2 of 5 label would be even shorter at 2.04 inches. This means that Code 39 is not well-suited for labeling very small items, as the barcode would either be too long to fit on the label or too small to be reliably scanned. Despite these limitations, Code 39's ability to be decoded with virtually any barcode reader and its widespread support across software and hardware platforms have ensured its continued use in specific sectors. | 
| Factor 1: Low Data Density | Low data density is one of the most common reasons for a symbology's decline. As supply chains require more information to be encoded on labels, the limitations of low-density symbologies become increasingly apparent. Code 39 is a prime example of a symbology whose design inherently limits its data capacity. | Code 39's structure, where each character is represented by a pattern of five bars and four spaces, with three elements being wide, results in a relatively large physical footprint for the amount of data encoded. As noted, a Code 39 barcode is longer than a Code 128 barcode carrying the same information. This becomes a significant problem in environments where label space is constrained. | In the automotive industry, for example, Code 39 has been widely used for Vehicle Identification Number (VIN) labeling and parts tracking. A VIN is a 17-character alphanumeric string. While Code 39 can easily encode this, the resulting barcode can be quite long. On a small automotive part, there may not be enough flat surface area to accommodate a Code 39 label of sufficient size to be scanned reliably. As parts have become smaller and more complex, the need for a more compact symbology has grown. This has led to a gradual shift toward Code 128, which can encode the same data in a significantly shorter space. | In the healthcare industry, Code 39 has been used under the HIBCC (Health Industry Business Communications Council) standards for labeling medical devices and pharmaceuticals. These labels often need to contain a significant amount of data, such as lot numbers, expiration dates, and unique device identifiers. The low density of Code 39 necessitates larger labels, which can be problematic for small vials, syringes, or surgical instruments. The industry has been moving toward 2D barcodes like Data Matrix, which can encode large amounts of data in a very small space, to address this issue. | The United States Department of Defense (DoD) was a major adopter of Code 39, standardizing it under MIL-STD-1189 for labeling military supplies and equipment. This standard mandated the use of Code 39 for identification markings on all items entering the DoD supply chain. However, the military's need to track increasingly complex equipment with more detailed logistics data eventually outpaced the capacity of Code 39. The large labels required were often impractical for small or oddly shaped items. This, combined with the need for more reliable scanning and error correction, eventually led the DoD to transition to Code 128 for linear barcodes and to adopt Data Matrix for items with limited labeling space. The cancellation of MIL-STD-1189 and its replacement by ANSI/AIM BC1/1995 for Code 39 was a significant blow to its dominance in this sector. | The logistics and warehousing sector has also been affected by Code 39's low density. While Code 39 is still used in some warehousing applications, the industry's shift toward more automated and data-rich systems has favored higher-density symbologies. In a modern fulfillment center, labels on packages and bins need to contain not only tracking numbers but also routing information, order details, and other metadata. Code 39's low density would require extremely large labels, which would be impractical and inefficient. This is why Code 128 and various 2D barcodes have become the norm in this sector. | The emergence of 2D barcodes like QR codes and Data Matrix codes represents a fundamental shift in data density. The GS1 'Sunrise 2027' initiative aims to migrate from 1D barcodes, such as the EAN/UPC codes found on retail products, to QR codes. This move is driven by the need to encode more data, such as batch numbers, expiration dates, and digital links to product information, within a limited space. QR codes can store hundreds of times more data than a linear barcode, making them ideal for the modern, data-driven supply chain. The European Union's proposal for a Digital Product Passport, which would be accessed via a QR code, is a concrete example of this trend. This passport would contain detailed information about a product's origin, materials, and environmental impact, demonstrating how the demand for data density is shaping the future of barcoding. | 
| Factor 2: Lack of Error Correction | The lack of robust error correction is another critical factor that can lead to a symbology's demise. In real-world environments, barcodes are subjected to various sources of damage: smudging, tearing, scratching, poor printing, and exposure to the elements. A symbology that cannot recover from such damage is inherently unreliable. While Code 39 is considered 'self-checking' to a limited degree, it lacks the dedicated error correction capabilities found in more modern symbologies. | Code 39's self-checking property means that a single erroneously interpreted bar cannot generate another valid character, thereby preventing misreads. However, it does not provide a mechanism to correct errors or to read a barcode that has been partially damaged. If a part of a Code 39 barcode is obscured or damaged, the scanner may not be able to read it at all, leading to a 'no-read' error. This is a significant drawback in industrial environments where barcodes are exposed to harsh conditions. | In the healthcare industry, the lack of error correction in Code 39 can have serious consequences. A medication label with a damaged barcode might fail to scan, requiring manual entry of the data, which is time-consuming and prone to human error. More importantly, the lack of robust error correction means that if a barcode is misread, there is little to no chance of recovery. While the self-checking feature prevents a single erroneous bar from creating a valid character, it does not guarantee that a damaged barcode can be accurately decoded. The shift toward 2D barcodes like Data Matrix, which incorporate sophisticated error correction algorithms such as Reed-Solomon codes, is largely driven by the need for reliability in this sector. These codes can sustain significant damage and still be fully readable, ensuring patient safety and operational efficiency. | The defense sector's experience with Code 39 illustrates the importance of error correction. In military logistics, labels often endure rough handling, exposure to moisture, and abrasion. The lack of error correction in Code 39 meant that damaged labels were often unreadable, hindering logistics operations. This is one of the reasons why the Department of Defense adopted Code 128, which includes a mandatory check digit for error detection, and later moved toward 2D barcodes with more robust error correction. | The emergence of 2D barcodes with advanced error correction is a key reason why older symbologies are being phased out. QR codes, for example, use Reed-Solomon error correction, which allows them to be read even if up to 30% of the symbol is damaged. This level of resilience is crucial for applications where barcodes are printed on packaging that may be crushed, folded, or smudged. The introduction of codes using Low-Density Parity-Check (LDPC) codes further enhances error correction capabilities, allowing for even higher data density and reliability. LDPC codes offer a better bit error performance compared to Reed-Solomon codes when noise is a significant factor, making them suitable for high-density 2D barcodes. As noted in research on the subject, these codes allow for flexible code lengths and high error-correcting capability, which are essential for high-density applications. This level of error correction is far superior to the simple self-checking mechanism of Code 39. | 
| Factor 3: Proprietary Nature | Proprietary symbologies, owned and controlled by a single company or organization, often face an uphill battle for widespread adoption. The need for specialized, often expensive, equipment to read and generate these codes creates a barrier to entry. Furthermore, the lack of an open standard can lead to vendor lock-in, where users are dependent on a single supplier for all their barcoding needs. | Code 39, in contrast, is an open standard. It was standardized as ANSI MH 10.8 M-1983 and later as ISO/IEC 16388. This openness has been a key factor in its longevity. Because the specification is publicly available and royalty-free, any manufacturer can create scanners, printers, and software that support Code 39. This has led to its ubiquity and low cost. | The proprietary nature of some symbologies has been a significant barrier to their adoption. For example, certain high-density 2D barcodes developed in the 1990s were proprietary, meaning that companies had to pay licensing fees and purchase specialized equipment to use them. While some of these found niche applications, none achieved the global ubiquity of open standards like QR Code. The QR Code, developed by Denso Wave, was intentionally made open and royalty-free, which was a primary driver of its widespread adoption in everything from marketing to supply chain management. As another example, color barcodes have been introduced to improve data density, but the need for specialized color classifiers and error correction to deal with chromatic distortions adds complexity and often relies on proprietary technology. This limits their adoption compared to standard black-and-white barcodes. | The GSI 'Sunrise 2027' initiative highlights the importance of open standards in driving adoption. The migration from EAN/UPC barcodes to QR codes is based on an open, globally recognized standard. This ensures that all stakeholders, from retailers to consumers, can participate without being locked into a proprietary system. The proposal to implement a Digital Product Passport using QR codes further underscores the role of open standards in shaping the future of barcoding. | 
| Factor 4: Poor Print Contrast | A barcode's readability depends on a sufficient difference in reflectivity between the dark bars and the light spaces. This is known as print contrast. A symbology with poor print contrast, either due to its design or the materials used, is difficult to scan reliably. | Code 39's design, with its variable width ratio and self-checking property, is somewhat forgiving of printing variations. However, it still requires a minimum print contrast to be read accurately. The use of low-contrast colors or substrates can make Code 39 unreadable. For instance, printing a Code 39 barcode in a light color on a white background, or in a dark color on a dark background, would result in poor print contrast and prevent scanning. In such cases, even a highly advanced scanner may not be able to decode the data due to the lack of contrast between the bars and spaces. | This is a particular challenge in industries where aesthetics are important. For example, in product packaging, there may be a desire to integrate the barcode seamlessly into the design. However, this can lead to poor print contrast and, consequently, unreliable scanning. This is one reason why some symbologies, like the color barcodes mentioned in research, have not seen widespread adoption despite their potential for high data density. The introduction of color adds a layer of complexity to print contrast requirements, as the scanner must distinguish not only between light and dark but also between different colors. This reliance on color classification makes them more susceptible to chromatic distortions introduced by the printing and scanning process. As a result, they often require more redundancy for error correction, which can offset their gains in data density and reliability. | 
| Factor 5: The Emergence of a Superior Standard | Perhaps the most common reason a symbology dies is the emergence of a superior standard. As technology evolves, new symbologies are developed that offer better performance in terms of data density, error correction, or other features. Users naturally migrate to these new standards, leaving the older ones behind. | Code 39's decline in many applications can be attributed to the emergence of Code 128 and 2D barcodes. Code 128, introduced in 1981, offers higher data density and includes a check digit for error detection. It can encode the full ASCII character set in a smaller space, making it a more efficient alternative to Code 39. As a result, Code 128 has largely replaced Code 39 in applications where space is at a premium or where error detection is critical. The Universal Postal Union, for example, recommends using Code 128 in all cases. | The emergence of 2D barcodes like QR Code and Data Matrix has been an even more transformative event. These symbologies can encode vast amounts of data, support sophisticated error correction, and can be read by cameras on smartphones, making them far more versatile than any 1D barcode. QR codes, with their ability to store up to 7089 numeric or 4296 alphanumeric characters, have become the standard for consumer-facing applications, from mobile ticketing to product information. Data Matrix codes, with their high data density in a small space, are used extensively in manufacturing, healthcare, and logistics. | The GS1 'Sunrise 2027' initiative is the most significant example of a superior standard displacing an older one. The initiative aims to migrate the global retail industry from EAN/UPC barcodes to QR codes powered by GS1. This is not an overnight change but a planned transition that will occur over several years, with both symbols appearing on products during the transition period. The QR code offers significant advantages: it can be scanned by consumers with their smartphones, it can store more data, and it can link to digital content like product information, promotions, and sustainability data. As of 2026, the trend toward QR codes is accelerating, with many retailers upgrading their point-of-sale systems to read 2D barcodes, and manufacturers preparing to print both 1D and 2D codes on their packaging. This will ultimately lead to the obsolescence of the linear barcode in the retail sector. | In the industrial sector, the rise of the Digital Product Passport is a similar story. The European Union's proposal to require a QR code containing detailed product information for various product categories, beginning with batteries for electric vehicles, is driving the adoption of 2D codes in previously 1D-dominated spaces. This passport will contain data on product composition, reparability, and disposal, far exceeding the capacity of a 1D barcode. This regulatory push is a powerful force for the adoption of a superior standard. | 
| Factor 6: High Scanner Cost | The cost of scanners is a significant factor in the adoption and survival of a symbology. Symbologies that require expensive, specialized scanning equipment are at a distinct disadvantage compared to those that can be read by standard, off-the-shelf scanners. | Code 39's success can be partly attributed to the fact that it can be read by virtually any barcode scanner, from the cheapest laser scanners to the most advanced imaging systems. The low cost and wide availability of Code 39 scanners have made it an accessible technology for a wide range of businesses. | However, the advent of 2D barcodes, which require imaging scanners, initially posed a cost barrier. These scanners are more expensive than the simple laser scanners used for 1D barcodes. This cost was a significant factor in the slow adoption of 2D barcodes in certain sectors. However, as imaging technology has become more affordable, this barrier has been eroded. As of 2024, over 80% of retail point-of-sale systems are equipped with cameras capable of scanning 2D barcodes. This widespread availability of capable hardware is now accelerating the transition to QR codes and other 2D symbologies. | The GS1 'Sunrise 2027' initiative is timed to coincide with this widespread availability of imaging scanners. The initiative is not a hard deadline for the disappearance of 1D barcodes but rather a target date by which the industry expects to have the capability to scan 2D barcodes at the point of sale. The cost of the necessary hardware is no longer the primary barrier; the main challenges now involve updating legacy systems and printing capabilities. The goal is to make 2D scanning a ubiquitous part of the retail infrastructure by 2027, paving the way for the eventual phase-out of linear barcodes. | 
| Industry Examples: The Fate of Code 39 | Automotive Industry | In the automotive industry, Code 39's alphanumeric capability made it a natural fit for VINs and parts labeling. However, its low data density has led to a gradual shift toward Code 128 and 2D Data Matrix codes for many applications. Modern automotive parts are often small and complex, and the need to encode detailed manufacturing data, including batch numbers and production dates, has made Data Matrix codes increasingly common. These codes can be marked directly on parts using laser etching, providing a durable and compact solution. | Healthcare | Code 39 has been used in healthcare under HIBCC standards for decades. However, the industry is moving toward 2D barcodes, particularly Data Matrix, for unit-of-use labeling and tracking medical devices. The FDA's Unique Device Identification (UDI) system requires a high level of data density and reliability, which Data Matrix provides. Furthermore, the use of QR codes on pharmaceutical packaging is gaining traction for providing patients with access to digital information, such as patient leaflets and recall notices. | Defense | The Department of Defense's adoption of Code 39 under MIL-STD-1189 was a major driver of its use in the defense sector. However, this standard has been cancelled, and the DoD has transitioned to Code 128 and Data Matrix codes to meet its evolving needs for logistics and asset tracking. The cancellation of the standard was a symbolic end to Code 39's dominance in that sector. | Logistics and Warehousing | Code 39 is still used in some logistics and warehousing applications, but Code 128 has largely replaced it for most uses. The higher data density and mandatory check digit of Code 128 make it a more reliable and efficient choice for tracking packages and inventory. Furthermore, the use of 2D barcodes for warehouse management is growing, as they can encode more information about the contents of a package or the location of a bin. | Postal and Shipping | The Universal Postal Union recommends using Code 128 in all cases, signaling the decline of Code 39 in this sector. While some postal services still use Code 39 for certain applications, the trend is toward more efficient and reliable symbologies. | 
| Summary and Conclusion | Symbologies die for a confluence of reasons: low data density, lack of error correction, proprietary nature, poor print contrast, the emergence of a superior standard, and high scanner cost. The story of Code 39 encapsulates this process. It was once a groundbreaking symbology, offering alphanumeric encoding in an era when most barcodes were numeric only. Its open standard, self-checking property, and compatibility with nearly all scanners made it an attractive choice. It became the workhorse of non-retail sectors, including automotive, healthcare, defense, and logistics. | However, as technology progressed, the limitations of Code 39 became increasingly apparent. Its low data density made it unsuitable for the modern, data-rich supply chain. The lack of a mandatory check digit made it less reliable than symbologies with dedicated error detection. The emergence of Code 128, with its higher density and built-in check digit, offered a superior linear alternative. The advent of 2D barcodes like QR Codes and Data Matrix provided a quantum leap in data capacity, error correction, and versatility. The availability of affordable imaging scanners finally removed the cost barrier to widespread 2D adoption. The GS1 'Sunrise 2027' initiative and the European Digital Product Passport are concrete examples of how these forces are converging to displace older symbologies on a global scale. While Code 39 may never completely disappear, its role has been significantly diminished, and its continued use is largely confined to legacy applications. The death of a symbology is not a sudden event but a gradual process of displacement, driven by the relentless pursuit of efficiency, reliability, and data capacity in the world of automatic identification. |
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cs@easiersoft.com