VODataService xs vt An extension to the core resource metadata (VOResource) for describing data collections and services. a reference to a standard specification. This typically refers to an IVOA standard but is not limited to such. a version of the standard that is recommended for use. the IVOA status level of this verison of the standard. an IVOA Recommendation an IVOA Proposed Recommendation an IVOA Working Draft not an IVOA standard or protostandard at this time. a reference to a standard service specification. This typically refers to an IVOA standard but is not limited to such. a generic description of one of the interfaces defined by this service standard. This element can provide details about the interface that apply to all implementations. Each interface element should specify a role with a value starting with "std:" or, if there is only one standard interface, is equal to "std". Applications that, for example, wish to build a GUI to the service on-the-fly would first access this generic description. Site-specific variations, such as supported optional arguments or site specific arguments, would be given in the actual implemented service description and overrides any common information found in this generic description. This generic interface description can be matched with the site-specific one using the role attribute.