This document sets a standard registration and maintenance mechanism for the registration of ISO 19150-4 compliant geographic information service ontologies. Registered ontologies shall conform to ISO 19150-4 which sets the structure of geographic information Web service ontologies. This document makes use of ISO 19135-1, Geographic information Procedures for item registration Part 1: Fundamentals whenever appropriate. This part of ISO 19150 does not define semantics operators, 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 purpose 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 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. This document is not intended to be an ISO Registration authority standard. However, it may be referenced by such a standard in the eventuality to create an ISO register. NOTE 1 The purpose of this document is different of the ISO/IEC 19763 family of standards, Information technology Metamodel framework for interoperability (MFI), which specifies an information artefact called the Registry Summary. The Registry Summary consists of information that describes administrative aspects, the summary of contents and the technical access method of the registry. However, registry based on this document could be described following 19763-6, Information technology Metamodel framework for interoperability (MFI) Part 6: Registry Summary. NOTE 2 ISO/IEC 18384-3 defines a formal ontology for service-oriented architecture (SOA), an architectural style that supports service orientation. The terms defined in this ontology are key terms from the vocabulary in ISO/IEC 18384-1. This document does not provide any architectural style to support service orientation although GeoWeb service definitions may benefit from ISO/IEC 18384-3.