A service provider indicates the URI endpoint and the encoding for messages used with that service. For example, a provider might have a URI of http://my.domain.com:8080/axis and an encoding of 'soap'. Another provider might have a URI of http://my.domain.com:8081/foo and an encoding of 'xmlrpc'. In this manner, all sorts of endpoints and encodings can be used to describe how to access a service. The service descriptor is the structure that describes all of the information about a service, including its providers (uri and encoding), name, wsdl, and more. An arbitrary list of key-value pairs can be used to add additional information to a service. Add a service description to the registry. Find service providers (endpoints and encodings) that can be used to call a service. Only the endpoint field of the returned service descriptor is filled in. The other fields may be either missing, null, or an empty string. Find a list of services that match a particular input query. Services can be selected based on their name, virtual organization, endpoint uri and/or encoding, and/or server certificate dn. Remove one or more services from the registry. The input service descriptors are used to select services to remove. If a particular field (such as minor_version) is null, or has a value of '*' or an empty string, then that field is not used to select matching services. A '*' can be used as part of a String field to select matching services. For example, 'uri=http://*.caltech.edu' will remove all services that are provided by servers in the caltech.edu domain. 'uri=*' will not remove all services with a uri, but instead indicate that the uri is not used to select services to remove.