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ISO 28560-2:2023 — RFID in Libraries: Encoding Data Elements with ISO/IEC 15962
A technical guide to flexible RFID data encoding for modern library systems
Introduction to ISO 28560-2:2023 and Library RFID Encoding
ISO 28560-2:2023 is the second part of the ISO 28560 series, which provides a comprehensive data model and encoding rules for radio frequency identification (RFID) tags used in library environments. This standard specifies how to encode a subset of data elements — drawn from the total set defined in ISO 28560-1 — using the encoding rules of ISO/IEC 15962. Unlike the fixed-length approach of Part 3, Part 2 adopts a flexible, object-identifier-based structure that allows variable-length and variable-format data to be organized on the RFID tag in any sequence.
ISO 28560-2 uses an object identifier (OID) structure to identify each data element, enabling different subsets of data elements to be encoded on different items within the same library. This flexibility is a key advantage for libraries with diverse collections.
The standard applies to all types of libraries — national, academic, public, corporate, special, and school libraries — and supports essential library workflows including user self-service, security gates, inventory management, and inter-library loan (ILL) processing. It operates at the 13.56 MHz high-frequency (HF) band specified in ISO/IEC 18000-3 Mode 1.
Data Elements and Encoding Architecture
ISO 28560-2 defines a rich set of data elements that can be stored on an RFID tag. The mandatory elements include the primary item identifier and the content parameter, while a wide range of optional elements support various library functions.
| ID | Data Element | Type | Description |
|---|---|---|---|
| 1 | Primary item identifier | Mandatory | Unique identifier for the library item |
| 2 | Content parameter | Mandatory | Version number indicating encoding rules |
| 3 | Owner institution (ISIL) | Optional | Institution identifier per ISO 15511 |
| 4 | Set information | Optional | Information about multi-volume sets |
| 5 | Type of usage | Optional | Loan category or usage restriction |
| 6 | Shelf location | Optional | Physical location within the library |
| 7 | ONIX media format | Optional | Media format code per ONIX standard |
| 8 | MARC media format | Optional | Media format code per MARC standard |
| 9 | Supplier identifier | Optional | Vendor/supplier identification |
| 10 | Order number | Optional | Purchase order reference |
| 11 | ILL borrowing institution | Optional | Inter-library loan partner |
| 12 | ILL transaction number | Optional | ILL transaction tracking |
| 13 | GS1 product identifier | Optional | Global trade item number (GTIN) |
| 14 | Alternative unique item identifier | Optional | Secondary ID scheme |
| 15 | Local data | Optional | Library-specific custom data |
| 16 | Title | Optional | Bibliographic title of the item |
Data Protocol and Encoding Rules
The encoding process follows a structured data protocol. The Application Family Identifier (AFI) distinguishes library tags from other RFID applications. The Data Storage Format Identifier (DSFID) further distinguishes between different encoding schemes within the library domain — for example, separating Part 2 flexible encoding from Part 3 fixed-length encoding.
ISO 28560-2 uses the ISO/IEC 15961-1 application command set and the ISO/IEC 15962 data encoding rules. These rules define how data elements are compacted, formatted, and written to the tag’s logical memory. The encoding supports data compaction techniques to maximize storage efficiency on memory-constrained RFID tags.
ISO 28560-2 and ISO 28560-3 are mutually exclusive on a single RFID tag. A library item must be encoded using either the flexible OID-based rules of Part 2 or the fixed-length rules of Part 3 — never both. This mutual exclusivity ensures unambiguous decoding.
Security, Privacy, and Implementation Considerations
ISO 28560-2 addresses several critical concerns for library RFID deployments:
Data Integrity
The standard mandates CRC (Cyclic Redundancy Check) mechanisms to detect data corruption on the tag. This is essential for ensuring that scanned items are correctly identified during self-checkout, returns, and inventory operations.
Item Security
Three complementary security mechanisms are defined: the dual AFI system for tracking item status (checked in vs. checked out), use of the unique tag ID (TID) programmed by the chip manufacturer, and Electronic Article Surveillance (EAS) features available in certain RFID chips. These mechanisms work together to prevent theft and unauthorized removal of library materials.
Privacy Protection
Privacy is a fundamental concern in library RFID systems. The standard recommends that personally identifiable information (PII) about library patrons should never be stored on the tag. Only item-related data should be encoded. This design principle ensures that RFID tags cannot be used to track individuals or their reading habits.
The dual AFI system is an elegant security solution: one AFI value indicates “item available for loan” while another indicates “item checked out.” Security gates at library exits can rapidly detect items that have not been properly checked out by interrogating the AFI value alone, without needing to read the full tag data.
Migration from Legacy Systems
The standard provides comprehensive migration guidance in its informative annexes. Libraries transitioning from barcode-based systems or proprietary RFID solutions can adopt ISO 28560-2 incrementally. The flexible encoding rules allow coexistence with legacy tags during a transition period, which may extend for years as older stock is gradually processed.
Performance Testing
RFID tag performance must be verified according to ISO/IEC 18046-3, and air interface conformance according to ISO/IEC 18047-3. These tests ensure that tags function reliably in real-world library environments, including近距离 reading at self-service kiosks and bulk reading at inventory wands.
Engineering Design Insights for Library RFID Systems
When designing a library RFID system based on ISO 28560-2, engineers should consider the following practical aspects:
Tag Memory Sizing: The standard’s flexible encoding allows variable-length data, but tag memory is finite. A typical HF RFID tag used in libraries offers between 512 bits and 2 Kbits of user memory. Engineers must carefully select which optional data elements to include based on the library’s operational requirements and the tag’s memory capacity.
Reader Compatibility: Not all RFID readers support the full ISO/IEC 15961-1 command set. When procuring equipment, verify that readers implement the required application commands defined in Annex B of the standard. This is particularly important for multi-vendor environments.
Data Compaction Strategy: The ISO/IEC 15962 encoding rules include several data compaction methods. Engineers should evaluate which compaction schemes provide the best balance between storage efficiency and processing overhead for their specific use case. For collections with predominantly ASCII text data, different compaction strategies apply than for collections with numeric-only identifiers.
A common deployment pitfall is failing to coordinate the AFI and DSFID values across all tags in a library consortium. If member libraries use different AFI values, shared items may not be readable across the consortium. Always define a统一的 AFI management policy before deployment.
Frequently Asked Questions
Q1: What is the difference between ISO 28560-2 and ISO 28560-3?
A: ISO 28560-2 uses flexible OID-based encoding following ISO/IEC 15962 rules, allowing variable-length data in any sequence. ISO 28560-3 uses a fixed-length basic block structure with predefined positions for each data element. Part 2 offers greater flexibility; Part 3 offers simpler decoding. They are mutually exclusive on a single tag.
A: ISO 28560-2 uses flexible OID-based encoding following ISO/IEC 15962 rules, allowing variable-length data in any sequence. ISO 28560-3 uses a fixed-length basic block structure with predefined positions for each data element. Part 2 offers greater flexibility; Part 3 offers simpler decoding. They are mutually exclusive on a single tag.
Q2: Can ISO 28560-2 tags be read by ISO 28560-3 readers?
A: Not directly. The DSFID value distinguishes the two encoding schemes. However, modern multiprotocol library RFID readers can detect the encoding type and apply the appropriate decoding rules automatically. The standard provides mechanisms for readers to distinguish between the two formats.
A: Not directly. The DSFID value distinguishes the two encoding schemes. However, modern multiprotocol library RFID readers can detect the encoding type and apply the appropriate decoding rules automatically. The standard provides mechanisms for readers to distinguish between the two formats.
Q3: How does ISO 28560-2 handle privacy concerns?
A: The standard explicitly recommends against storing patron PII on RFID tags. Only item-related metadata (identifier, location, media type) should be encoded. The AFI-based security model allows theft detection without revealing item identity, further protecting patron privacy.
A: The standard explicitly recommends against storing patron PII on RFID tags. Only item-related metadata (identifier, location, media type) should be encoded. The AFI-based security model allows theft detection without revealing item identity, further protecting patron privacy.
Q4: What is the role of the ISIL in ISO 28560-2?
A: The ISIL (International Standard Identifier for Libraries and Related Organizations, per ISO 15511) identifies the owning institution. This is critical for resource sharing and inter-library loan scenarios, enabling libraries to identify the source of each tagged item across a consortium or national network.
A: The ISIL (International Standard Identifier for Libraries and Related Organizations, per ISO 15511) identifies the owning institution. This is critical for resource sharing and inter-library loan scenarios, enabling libraries to identify the source of each tagged item across a consortium or national network.
