Overview
ISO 8879:1986/Cor 2:1999 is Technical Corrigendum 2 to the original ISO 8879 standard for the Standard Generalized Markup Language (SGML). Published in 1999, this corrigendum corrects terminology, clarifies ambiguous provisions and adds new normative and informative annexes-most notably Annex K (Web SGML Adaptations)-to address defects revealed by SGML adaptations for the World Wide Web, intranets and extranets. The changes are designed to resolve errors and ambiguities without causing existing conforming documents to become non‑conforming.
Key topics and technical requirements
- Terminology updates
- All occurrences of “element declaration” → “element type declaration”
- All occurrences of “element set” → “element type set”
- Revision of definition 4.223 owner identifier to clarify owner vs. object ownership
- Annex K - Web SGML Adaptations (normative)
- Remedies ambiguities and errors specific to Web use while remaining applicable to all SGML uses
- References groves and property sets as defined in HyTime (ISO/IEC 10744) and DSSSL (ISO/IEC 10179)
- Allows documents to indicate conformance to the annex via the SGML declaration (e.g., minimum literal
"[ISO 8879:1986](/iso-8879-1986) (WWW)")
- Specifies parser behavior: an SGML parser that supports Annex K must be able to parse documents that do not claim conformance and produce the same grove
- Definitions and constraints
- Detailed definitions: fully-declared, fully-tagged, amply-tagged, type-valid, integrally-stored, reference-free, and external-reference-free documents
- Guidance on entity constraints to ease processing in environments with limited access to external entities
- SGML declaration and concrete syntax
- Syntax for SGML declaration body, capacity set, concrete syntax, quantity set, and predefined data character entities
- Rules for markup minimization features (DATATAG, OMITTAG, RANK, SHORTTAG) and empty element ending rules (EMPTYNRM)
- Options for SHORTTAG behavior (start-tag, end-tag, attribute options) including NETENABL modes
Practical applications and users
- Target users:
- SGML parser and validator implementers
- Document authors and maintainers working with legacy SGML on the Web, intranets or extranets
- Tool and CMS vendors supporting SGML workflows, DTDs and conversions to HTML/XML
- Standards bodies and archivists ensuring backward-compatible SGML processing
- Practical value:
- Improves interoperability of SGML on the Web by clarifying parser expectations and markup minimization
- Helps implement robust DTD validation and safer handling of external entities in distributed environments
- Enables self-identifying SGML documents to declare Web‑oriented conformance via the SGML declaration
Related standards
Keywords: SGML, ISO 8879, Technical Corrigendum, Web SGML adaptations, DTD, SGML declaration, markup minimization, predefined entities, parsers, HyTime, DSSSL.