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ISO 690:2021 — The Foundation of Relaton
ISO 690:2021 (Information and documentation — Guidelines for bibliographic references and citations to information resources) is the international standard that defines how bibliographic references should be structured. It applies to all kinds of information resources — monographs, serials, patents, cartographic materials, electronic resources, research datasets, music, recorded sound, archival sources, and more.
Notably, ISO 690 states:
"This document does not specify a data model for machine‑readable citations."
Relaton fills that gap. It is the machine-readable information model implementation of ISO 690.
Four Principles
ISO 690 establishes four principles for creating references:
Principle 1: Ensure metadata accuracy
The metadata in a reference should be accurate for crediting the creator of the cited resource and for enabling the reader to locate it. Metadata should be sourced from the cited resource itself (title page, embedded metadata, cover) or from authoritative external sources.
Principle 2: Prioritize identification and retrieval
A reference should enable the reader to identify and retrieve the cited resource. Providing actionable persistent identifiers (URIs, DOIs) is a direct manifestation of this principle.
Principle 3: Unify reference presentation
A uniform presentation helps readers understand metadata across different resource types and makes it easier for authors to apply consistent practices.
Principle 4: Determine appropriate specificity
A reference should have an appropriate level of specificity — e.g., distinguishing an article within a journal issue from the issue itself.
14 Data Elements
ISO 690 defines 14 categories of data elements that compose a bibliographic reference. Each maps to a corresponding entity in the Relaton model:
| # | ISO 690 Data Element | Relaton Entity | Description |
|---|---|---|---|
| 1 | Creator | Contributor | Persons, organizations, and their roles |
| 2 | Title | Title | Title types, scripts, multilingual titles |
| 3 | Component parts | Citation | Host items, extents, contained parts |
| 4 | Medium designation | Medium | Content type, carrier, physical size |
| 5 | Edition / version | Edition | Versioning and edition statements |
| 6 | Date | Production | Publication, access, creation dates |
| 7 | Production information | Production | Place, publisher, distributor |
| 8 | Numeration | Numeration | Extent, pagination, size, volumes |
| 9 | Series | Series | Series title and numbering |
| 10 | Standard identifiers | Identifiers | ISBN, ISSN, DOI, URNs, document IDs |
| 11 | Location / access | Location | URLs, access points, availability |
| 12 | Surrogate | — | Thumbnail, preview representation |
| 13 | Relations | Relations | 60+ typed relations between documents |
| 14 | Additional information | Additional Info | Keywords, classification, notes |
Relaton extends each data element beyond what ISO 690 requires, adding standards-specific fields: document stages, supplements, amendment tracking, flavor-specific extensions, and more.
16 Resource Types
ISO 690 §8 defines citation guidelines for 16 categories of information resources:
| Resource Type | Examples |
|---|---|
| Monographs | Books, reports, theses |
| Component parts of monographs | Chapters, contributions |
| Continuing resources (serials) | Journals, newspapers, annuals |
| Programs and applications | Software, apps |
| Cartographic materials | Maps, atlases, globes |
| Audiovisual resources | Films, recordings, broadcasts |
| Graphic works | Photographs, prints, drawings |
| Music | Scores, recordings |
| Patents | Patent applications, granted patents |
| Reports | Technical reports, working papers |
| Archival materials | Fonds, collections, records |
| Research datasets | Data files, databases |
| Web resources | Websites, web pages |
| Social media | Posts, threads, profiles |
| Unpublished works | Manuscripts, preprints |
| Preprints | Non-peer-reviewed manuscripts |
Relaton's Bibitem Types entity defines a union of ISO 690 resource types and BibTeX entry types, providing comprehensive coverage of citable resources.
Five Citation Systems
ISO 690 Annex A defines five citation systems for linking in-text citations to their references:
| System | In-text format | Example |
|---|---|---|
| Name-date (Harvard) | Author + year | (Crane 1972) |
| Numeric | Sequential number | [26] |
| Named tag | Author-chosen tag | [ISO44001] |
| Running notes | Footnote numbers | ³² |
| Implied | Document identifier | ISO 44001:2017 |
Relaton supports all five systems through relaton-render, which provides configurable templates for each citation style. The implied system (using document identifiers directly) is particularly relevant for standards documents, where publications are routinely cited by their PubID (e.g. ISO 19115-1:2014 or IETF RFC 8446).
What Relaton Extends Beyond ISO 690
While Relaton implements the full ISO 690 data model, it adds significant capabilities for the standards ecosystem:
- 60+ typed document relations — ISO 690 defines a few relation types; Relaton defines a comprehensive taxonomy including
replaces,amends,corrigends,hasPart,complements,obsoletes,updates,derives, and many more - Document lifecycle tracking — publication stages, supplements, amendment tracking
- Flavor-specific extensions — each SDO can add organization-specific metadata without modifying the core model
- Auto-fetch by publication identifier — given only a PubID, Relaton retrieves structured metadata from 27+ SDO datasets
- Multiple serialization formats — YAML, XML, BibTeX, AsciiBib, JSON-LD
Explore the Relaton model → | Extensions beyond ISO 690 → | Flavor model extensions →