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ISO 690 Guidelines
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ISO 690:2021 — Information and documentation — Guidelines for bibliographic references and citations to information resources. Available from the ISO Store.
ISO 690:2021 is the international standard governing how bibliographic references should be structured. It covers every kind of citable resource — books, journal articles, patents, datasets, software, social media posts, audiovisual works, archival materials, maps, music, and more.
The standard makes an important declaration:
This document does not specify a data model for machine-readable citations.
Relaton fills this gap. It provides the machine-readable information model that ISO 690 deliberately left unspecified.
What ISO 690 Covers
The standard is organized into four major areas:
| Area | Clause | Content |
|---|---|---|
| Principles | §4 | Four principles governing all references |
| Guidelines | §5–6 | Seven guidelines for creating references; metadata sourcing |
| Data Elements | §7 | 14 categories of bibliographic metadata |
| Resource Types | §8 | Citation rules for 16 kinds of information resources |
| Citation Systems | Annex A | Five systems for linking in-text citations to references |
| Persistent References | Annex B | Making web citations durable |
Key Terminology
ISO 690 defines precise terms that Relaton implements as model entities:
| Term | Definition | Relaton Entity |
|---|---|---|
| Information resource | Any work, manifestation, or item in physical or digital form that contributes to human knowledge | BibliographicItem |
| Work | A distinct intellectual or artistic creation | FRBR Work level |
| Manifestation | The physical embodiment of a work (print, digital, etc.) | Medium, format fields |
| Component part | An entity that forms part of a host document (article, chapter, track) | Citation / extent |
| Continuing resource | A resource issued over time with no predetermined conclusion | Serial handling |
| Persistent identifier (PID) | A unique identifier ensuring permanent access regardless of location | docidentifier |
| Reference | Data describing a resource sufficiently precise to identify and retrieve it | The entire model |
A single work may have multiple manifestations (print book, e-book, audiobook). ISO 690 requires that the reference identify the specific manifestation used, since content can differ between formats.
The Gap ISO 690 Left
ISO 690 specifies what metadata belongs in a reference and how it should be presented for human readers. It deliberately does not specify:
- A formal data model with typed fields and validation rules
- A machine-actionable encoding of the 14 data elements
- A way to programmatically parse, compare, or transform references
- Inter-document relations beyond a handful of types
These are the problems Relaton solves.
Relaton's Implementation
| ISO 690 Concept | Relaton Implementation |
|---|---|
| 4 principles | Reflected in the model design — accuracy through typed fields, retrieval through identifiers, uniformity through configurable renderers, specificity through structured component parts |
| 14 data elements | Each maps to one or more Relaton entities (Contributor, Title, Date, Series, etc.) |
| 16 resource types | Covered by the BibItemType enumeration, extended with BibTeX types |
| 5 citation systems | Supported by relaton-render with configurable templates |
| 7 guidelines | Enforced by the model's structure — the model prevents inaccurate metadata by design |
What Relaton Adds Beyond ISO 690
- 50+ typed document relations — ISO 690 mentions translations and adaptations; Relaton defines a comprehensive FRBR-based taxonomy
- Document lifecycle tracking — publication stages, supplements, amendment tracking
- Flavor-specific extensions — each SDO adds organization-specific metadata through the
extblock - Auto-fetch by publication identifier — given a PubID, Relaton retrieves structured metadata from 27+ SDO datasets
- 18 date types (vs. ISO 690's ~3) — published, accessed, created, implemented, obsoleted, confirmed, and more
- 12 contributor roles (vs. ISO 690's ~4) — author, editor, realizer, performer, translator, adapter, publisher, distributor, owner, authorizer, enabler, subject
- Multiple serialization formats — YAML, XML, JSON, BibTeX, AsciiBib
Explore the Companion Guide
- Principles — The four principles and seven guidelines for creating accurate references
- Data Elements — All 14 data element categories with rules and examples
- Resource Types — Citation guidelines for 16 kinds of information resources
- Citation Systems — Five methods for linking in-text citations to references