Terminology Definition Description Language (TDDL) 1.0

TDDL is an extension of XHTML Basic designed to describe terminologies. TDDL incorporates RDF Schema concepts, syntax and functionality. This document is a TDDL description of TDDL.


TDDL is designed to serve as a way to define terminologies in a way that is both human and machine readable. It is inspired by and borrows concepts from:

TDDL incorporates RDF Schema into XHTML as an extension of XHTML Basic.

This draft is highly experimental.


The root of all things in TDDL is Resource. Every Resource is itself an rdf:Resource. Literal things can be encoded as URIs via the data: scheme.


A tddl:Class is a Class derived from rdfs:Class.


A Property is a Class derived from rdfs:Property.


The subClassOf a Class defines the class as derived from another class.

tddl:subClassOf is derived from RDF Schema subClassOf.


The subPropertyOf a Property defines the property as derived from another property.

tddl:subPropertyOf is derived from RDF Schema subPropertyOf.


The range of a Property defines what value a Property may have.

tddl:range is derived rdfs:range.


The domain of a Property defines which Classes a Property may pertain to. A Property may have multiple domains.

tddl:domain is derived rdfs:domain.



A tddl:type is an rdf:type.


A tddl:resource is a rdf:resource. It is an attribute whose value is a URI reference

id and about

tddl:about is derived from rdf:about.

A Class,Property, or Resource may have either id or tddl:about but not both