RDFa Vocabulary for Term and Prefix Assignment, and for Processor Graph Reporting

This document describes the RDFa Vocabulary for Term and Prefix Assignment. The Vocabulary is used to modify RDFa 1.1 processing behavior. The URI of the vocabulary is http://www.w3.org/ns/rdfa# (abbreviated by rdfa: in this document). Turtle and an RDF/XML versions of the vocabulary are also available. The vocabulary is published by W3C

For a precise definition of these vocabulary elements, see the RDFa Core 1.1 specification.

Term and prefix assignment vocabulary

This vocabulary contains terms to define prefix mappings and term assignments; these can be used as part of the @profile mechanism of RDFa 1.1.

The vocabulary defines three classes :

• rdfa:PrefixOrTermMapping is the top level class for prefix or term mappings.
• rdfa:PrefixMapping is the class for prefix mappings.
• rdfa:TermMapping is the class for term mappings.

Properties

• rdfa:prefix: defines a prefix mapping for a URI; the value is supposed to be a NMTOKEN; it is used on prefix mapping instances.
• rdfa:term: defines a term mapping for a URI; the value is supposed to be a NMTOKEN; it is used on prefix mapping instances.
• rdfa:uri: defines the URI for either a prefix or a term mapping; the value is supposed to be an absolute URI; it is used on either prefix or term mapping instances.
• rdfa:vocabulary: defines an absolute URI to be used as a default vocabulary; the value is can be any string; for documentation purposes it is advised to use the string 'true' or 'True'.

Processor Graph Reporting Vocabulary

The reporting mechanism is based on a hierachy of classes. rdfa:PGClass is the top level class of the hierarchy, with three subclasses: rdfa:Error is the class for all error conditions, rdfa:Warning is the class for all warnings, and rdfa:Info is the class for all informations.

RDFa 1.1 Core defines the following error and warning conditions:

• rdfa:DocumentError: error condition; to be used when the document fails to be fully processed as a result of non-conformant host language markup
• rdfa:VocabReferenceError: warning; to be used when the value of a @vocab attribute cannot be dereferenced, hence the vocabulary expansion cannot be completed
rdfa:UnresolvedCURIE: warning; to be used when a CURIE prefix fails to be resolved
• rdfa:UnresolvedTerm: warning; to be used when a Term fails to be resolved
• rdfa:PrefixRedefinition: warning; to be used when a prefix, either from the initial context or inherited from an ancestor node, is redefined in an element

RDFa processors may add their own subclasses in their own namespace.

A specific property, rdfa:context, provides extra context for the error, eg, http response, an XPointer/XPath information, or simply the URI that created the error.

Term for vocabulary expansion

A specific property, usesVocabulary, provides a relationship between the host document and a vocabulary defined using the @vocab facility of RDFa1.1.

Property Copying Terms

The terms for property copying allow properties associated with a resource to be copied to another resource; for more details see the relevant section in the HTML+RDFa 1.1 document. The terms being used are:

• rdfa:Pattern: Class to identify an (RDF) resource whose properties are to be copied to another resource
• rdfa:copy: identifies the resource (i.e., pattern) whose properties and values should be copied to replace the current triple (retaining the subject of the triple).