alist of the representation formats supported by the service. Example: text/html, text/xml, application/json the version or release identifier of the service the default format used by the service unless otherwise specified the set of namespaces recognized by this service. Because many namespace identifiers tend to be cryptic (i.e. HL7 OIDs, BioPortal URL's, etc.), <i>knownNamespace</i> includes the namespace name, an optional URI \emph{and} a place to provide textual detail describing what the namespace references. Note that namespace names must be unique across an entire CTS2 implementation - the same namespace name cannot represent one namespace in code system A and a second in code system B. Note also that namespace names are \emph{local} to a service instance. Information that is communicated between service instances, recorded in data tables or client software \emph{must} use full URIs. a reference to the individual or organization that provides the service. the set of service profiles that are supported by this service implementation a description of the service, its use, etc. a short name that identifies the particular service and implementation the particular implementation type(s) supported by this profile the match algorithms that can be used in filters for this service instance the set of model attributes that can be referenced in filter instances for the given service implementation The set of properties that are used in one or more instances of the resource represented by this service. This list includes all properties that can be used in queries in this service, independent of the <i>entryState </i>or temporal state of the resource(s) being searched. The set of version tags known to the service. All services must recognize the "CURRENT" tag, although interpretation is service specific. a <i>DirectoryURI </i>that resolves to the set of versions known to the service Return the number of elements currently represented by the supplied directory URI. Resolve the supplied <i>DirectoryURI</i> and return the set of catalog entries it represents. The <i>referenceLanguage</i> is not supported by the service The change set specified could either not be read or located by the service. The <i>changeSetContext</i> is recognized by the service, but its state is not <i>OPEN</i>. One or more <i>changeSetContext</i> is not supported by the service Errors that can occur in sort and/or filter parameters The <i>format</i> is not supported by the service implementation The <i>timeLimit</i> was exceeded by the service. The supplied <i>directory</i> URI is not valid The type represented by the supplied <i>directory</i> URI is not the one required by the service invocation. Retrieve the specified code system version directory.Retrieve a change set as an iterable resource - a handy function for viewing large change sets The <i>referenceLanguage</i> is not supported by the service The change set specified could either not be read or located by the service. The <i>changeSetContext</i> is recognized by the service, but its state is not <i>OPEN</i>. One or more <i>changeSetContext</i> is not supported by the service Errors that can occur in sort and/or filter parameters The <i>format</i> is not supported by the service implementation The <i>timeLimit</i> was exceeded by the service. The supplied <i>directory</i> URI is not valid The type represented by the supplied <i>directory</i> URI is not the one required by the service invocation. Retrieve a code system version directory containing the specified entities.Retrieve a code system version directory containing the specified entities. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service The supplied <i>directory</i> URI is not valid The type represented by the supplied <i>directory</i> URI is not the one required by the service invocation. Return a <i>DirectoryURI</i> that references the set of all elements represented by <i>directory</i> that match the criteria specified in <i>filter.</i> Remove any of the elements in <i>elementsToRemove</i> from <i>initialSet </i>if present. Elements in <i>elementsToRemove</i> that are not in <i>initialSet</i> are ignored. Return a directory that represents the set of elements that are common to the two supplied directories. Note that both DirectoryURIs must represent resources of the same type. Return a directory that represents the combination of the contents of the supplied two supplied directories, with duplicate entries removed. Note that both of the directory URIs must resolve to entries of the same type.