After three and a half years of intensive work and a long formal process, ISO TC46/SC9 WG8 has finalized work on Part 1 of the new thesaurus standard. It has been published by ISO on August 18, 2011.
ISO 25964-1 “Information and documentation — Thesauri and interoperability with other vocabularies — Part 1: Thesauri for information retrieval”, is a standard for development of thesauri and exchange of thesaurus data, covering both mono- and multilingual thesauri.
It has been developed (cf. ) as an extensive revision and extension of ISO 2788 and ISO 5964 (1985/6), based on BS 8723 (2005-2008), to include the following main sections:
2 Terms and definitions
3 Symbols, abbreviated terms and other conventions
4 Thesaurus overview and objectives
5 Concepts and their scope in a thesaurus
6 Thesaurus terms
7 Complex concepts
8 The equivalence relationship, in a monolingual context
9 Equivalence across languages
10 Relationships between concepts
11 Facet analysis
12 Presentation and layout
13 Managing thesaurus construction and maintenance
14 Guidelines for thesaurus management software
15 Data model
16 Integration of thesauri with applications
17 Exchange formats
Annex A (informative) Examples of displays found in published thesauri
Annex B (informative) XML Schema for data exchange
Part 1 can be bought and downloaded from ISO  or ordered from national standards bodies such as BSI, DIN, ANSI, AFNOR. It is available in PDF or print, in English language only. Standards distributors may sell it as well and certain reference libraries include it in their holdings.
Freely available is, however, the XML schema, that has been developed for exchange of thesaurus data (an Annex to the standard), cf. . It is underpinned by a UML data model that provides for all the features a thesaurus may include, e.g. terms, relations among terms, concepts, relations among concepts, arrays, concept groups etc. Some constraints have been incorporated in the schema to ensure the quality of the represented thesauri.
The schema can be accessed without charge or password control at the NISO site  containing the schema and an introduction to it, an XML test example, HTML documentation files and an errata page for the standard.
A presentation at the recent NKOS 2011 workshop at TPDL in Berlin  did focus on the XML schema and made a comparison with the SKOS schema, pointing to necessary SKOS extensions.
Part 2 of the new standard, “Interoperability with other vocabularies”, covers mapping between thesauri and other types of vocabulary, such as classification schemes, file plans for records management, taxonomies, subject heading schemes, ontologies, terminologies, name authority lists, and synonym rings.
As ISO DIS 25964-2 (Draft International Standard) it has been submitted mid October for circulation among the member bodies of TC46/SC9 (Information and documentation/ Identification and description) and for comments.
Publication of Part 2 can be expected in 2012.
National standards bodies make the text available, applying different policies, however. BSI will, most probably, make it available to everybody during a commenting period, free of charge and passwords (cf. ).