Unique identifier for OWL 2 DL.

'http://www.w3.org/ns/owl-profile/DL' is the URI. OWL DL is defined by the OWL 2 Structural Specification and Functional-Style Syntax and the OWL 2 Web Ontology Language, Direct Semantics documents, part of the the OWL 2 W3C Recommendation.

For more information about OWL, please refer to the the OWL 2 Document Overview Recommendation.