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. Return the number of elements currently represented by the supplied directory URI. 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. the date and time that the last change was applied to the service. a <i>DirectoryURI</i> that resolves to the set of all changes that have been applied to the service the date and time of the first change that occurred in the service. Note that the granularity of "change" is the application of an import operation or the submission of a change set, so the first change might encompass the loading of an entire ontology or even a complete ontology with history. Retrieve a change set as an iterable resource - a handy function for viewing large change sets Return the change set referenced by the supplied URI. Return a directory of <i>EntityDescriptions</i> matching the supplied namespace/name or URI whose <i>ChangeSet \\</i> <i>officialEffectiveDate</i> falls between <i>fromDate </i>and <i>toDate</i>. The order of the dates controls the return order - if <i>fromDate </i>is later than <i>toDate</i> the return order is latest to earliest, otherwise it is earliest to latest.Return a list of records that reflects the change in the catalog entry over the specified time span. Records will be sorted from earliest to latest if (a) <i>fromDate</i> is omitted or (b) <i>toDate</i> is omitted, or (c) <i>fromDate </i> is earlier than <i>toDate</i>. In all other cases, records will be sorted from latest to earliest. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service Return a directory of <i>EntityDescriptions</i> matching the supplied namespace/name or URI whose changes became visible in the service between <i>fromDate</i> and <i>toDate</i>. The order of the dates controls the return order - if <i>fromDate </i>is later than <i>toDate</i> the return order is latest to earliest, otherwise it is earliest to latest. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service Select from the set of <i>ChangeSet</i>s that contain one or more changes for the referenced entity the <i>ChangeSet</i> that has the earliest <i>officialEffectiveDate</i> and return the first change for the named entity in the set.Return an catalog entry that reflects the state of the entry when it first appeared in the service. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service Get the first change that was applied to the named entity from the perspective of the service. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service Select from the set of <i>ChangeSet</i>s that contain one or more changes for the referenced entity the <i>ChangeSet</i> that has the latest <i>officialEffectiveDate</i> and return the last change for the named entity in the set. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service Get the last change that was applied to the named entity from the perspective of the service. The supplied namespace name is not one that is known to the service. The <i>EntityNameOrURI</i> is not known to the service A service that provides a historical perspective on what changes occurred to a given <i>EntityDescription</i>.