Overview
ISO/IEC 13250-6:2010, "Information technology - Topic Maps - Part 6: Compact syntax", defines the Compact Topic Maps (CTM) text notation and the mapping from that notation to the Topic Maps data model (ISO/IEC 13250-2). CTM provides a lightweight, human-readable alternative to the XML interchange syntax (ISO/IEC 13250-3) and is specified using an EBNF grammar. CTM is intended for manual authoring, readable examples, and as a syntactic basis for related languages such as TMCL and TMQL.
Key technical topics and requirements
- Compact syntax (CTM): A text-based notation for representing instances of the topic maps data model. The syntax is fully specified via an EBNF grammar.
- Mapping to the data model: CTM describes deserialization rules to produce valid instances of the ISO/IEC 13250-2 data model. Serialization is implicit but implementations should preserve canonicalization (ISO/IEC 13250-4).
- Deserialization inputs and rules:
- Optional IANA charset name and byte stream (UTF-8 default rules and BOM handling).
- Mandatory document IRI used to assign item identifiers.
- Optional wildcard-iri and wildcard-counter for wildcard-generated locators.
- IRI handling and abbreviations:
- IRIs from delimited strings and QNames (prefix:local) are supported; QNames resolve via prefix directives.
- Conformance to IETF RFC 3986/3987 for IRI/URI rules.
- Topic identity forms:
- Topics may be identified by item identifiers (^) , subject identifiers, or subject locators (=), with merging behavior defined by the data model.
- Language constructs:
- Whitespace and comment rules (single-line and nested multiline comments).
- Literals and escape sequences.
- Components covered: topics, names, occurrences, variants, associations, templates, directives (prefix, include, mergemap), encoding and version directives.
- Conformance: Every CTM instance must deserialize into a valid ISO/IEC 13250-2 data model instance.
Practical applications and users
- Who uses it:
- Knowledge engineers, semantic architects, and documentation authors who need a concise, readable interchange format for topic maps.
- Developers implementing Topic Maps tools (editors, parsers, serializers) or authoring TMCL/TMQL test cases.
- Educators and technical writers creating examples and documentation.
- Use cases:
- Manual authoring of topic maps and small knowledge bases.
- Embedding human-readable examples in standards, papers, or tutorials.
- Rapid prototyping of topic-map-based applications and transformations.
Related standards and references
Keywords: ISO/IEC 13250-6, Compact Topic Maps, CTM syntax, Topic Maps, EBNF grammar, deserialization, QNames, IRI, topic identity.