Semantically-Interlinked Online Communities

Regarding underlying technology, SIOC relies heavily on W3C's RDF technology, an open Web standard that can be freely used by anyone. This visual layout and structure of the specification was adapted from the FOAF Vocabulary Specification by Dan Brickley and Libby Miller. The SIOC (Semantically-Interlinked Online Communities) Core Ontology provides the main concepts and properties required to describe information from online communities (e.g., message boards, wikis, weblogs, etc.) on the Semantic Web. This document contains a detailed description of the SIOC Core Ontology. NOTE: This section describes the status of this document at the time of its publication. Other documents may supersede this document. Authors welcome suggestions on the SIOC Core Ontology Namespace and this document. Please send comments to the SIOC developers' mailing list (SIOC-Dev), public archives are available. This document may be updated or added to based on implementation experience, but no commitment is made by the authors regarding future updates. Semantically-Interlinked Online Communities, or SIOC, is an attempt to link online community sites, to use Semantic Web technologies to describe the information that communities have about their structure and contents, and to find related information and new connections between content items and other community objects. SIOC is based around the use of machine-readable information provided by these sites. The SIOC Core Ontology described in this document is the foundation for Semantically-Interlinked Online Communities. Developers can use this ontology to express information contained within community sites in a simple and extensible way. The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 . An alphabetical index of SIOC terms, by class (concepts) and by property (relationships, attributes), are given below. All the terms are hyperlinked to their detailed description for quick reference. The SIOC Core Ontology definitions presented here are written using a computer language (RDF/OWL) that makes it easy for software to process some basic facts about the terms in the SIOC Core Ontology, and consequently about the things described in SIOC documents. A SIOC document, unlike a traditional Web page, can be combined with other SIOC and RDF documents to create a unified database of information. SIOC provides a unified vocabulary for content and interaction description: a semantic layer that can co-exist with existing discussion platforms. There is a post titled "Creating connections between discussion clouds with SIOC" created at 09:33:30 on 2006-09-07 written by a user "Cloud" on topics "Blogs" and "Semantic Web" with contents described in sioc:content . More information about its author can be found at The post has a reply and detailed SIOC information about this reply can be found at This simple example uses only two classes of SIOC objects: sioc:Post and sioc:UserAccount . There are other classes in SIOC used to describe more information about forums, sites, communities and other objects. SIOC documents may use other existing ontologies to enrich the information described. Additional information about the creator of the post can be described using the FOAF Vocabulary . Rich content of the post (e.g., HTML representation) can be described using AtomOwl or the RSS 1.0 Content Module . For more information on classes and properties from other vocabularies that are often used together with SIOC, see the section on external classes and properties . SIOC is managed as a collaborative effort amongst members of the Unit for Social Semantics at the Data Science Institute , NUI Galway (funded by SFI ) and Semantic Web developers on the SIOC developers' mailing list (SIOC-Dev). The name "SIOC" is an acronym for "Semantically-Interlinked Online Communities", and is coinc