From OWL Web Ontology Language Guide ( 2004-02-10) an RDFS datatype, almost always one of the built-in non-list XML Schema datatypes

Definition: From XML Schema [XML Schema part 2]: A 3-tuple, consisting of a) a set of distinct values, called its value space, b) a set of lexical representations, called its lexical space, and c) a set of facets that characterize properties of the value space, individual values or lexical items.

A term used by RELAX NG to qualify the content of a simple content element or attribute. Datatypes shouldn't be confused with XML 1.0 element types; those are called element names by RELAX NG.

an abstract notion that can be used to define an attribute or an element

Definition: A 3-tuple, consisting of a) a set of distinct values, called its value space, b) a set of lexical representations, called its lexical space, and c) a set of facets that characterize properties of the value space, individual values or lexical items. This definition is taken from XML Schema [XML Schema part 2].