This document establishes a standard registration and maintenance mechanism for the registration of ISO 19150-4-conformant geographic information service ontologies. This document makes use of ISO 19135-1 whenever appropriate. This document does not define semantics operators or rules for ontologies, and does not develop any application ontology. In relation to ISO 19101-1:2014, 6.2, this document defines and formalizes the following purposes of the ISO geographic information reference model: –     geographic information service components and their behaviour for data processing purposes over the Web; and –     OWL ontologies to cast ISO/TC 211 International Standards to benefit from and support the Semantic Web. In relation to ISO 19101-1:2014, 8.3, this document addresses the Application:Procedural foundation of the ISO geographic information reference model.