The SDMXMessage.xsd is used to import all SDMXML types so as to be referenced in the WADL. The SDMXRestTypes.xsd defines various types used by the WADL's parameters e.g. key pattern, latest and all values. The base URL is a sample. The service base can be named according to the implementor needs The MaintainableArtefact resource type defines the common behaviour for all the maintainable artefacts, which inherit from it.