An entry in a catalog of maps - organized collections of rules that describe how information encoded using one set of value meanings can be transformed into a second, related set of meanings. A map catalog contains information about who is responsible for creating and distributing the rules, the source code system or value set, the target code system or value set, how often the rules are updated, how they are distributed, etc. An entry in a catalog of maps - organized collections of rules that describe how information encoded using one set of value meanings can be transformed into a second, related set of meanings. A map catalog contains information about who is responsible for creating and distributing the rules, the source code system or value set, the target code system or value set, how often the rules are updated, how they are distributed, etc. the CodeSystem from which the source codes in the Map are drawn. Note that the source codes may be drawn from either a CodeSystem or a ValueSet, but not both. the ValueSet from which the source codes in the Map are drawn. Note that the source codes may be drawn from either a CodeSystem or a ValueSet, but not both. the CodeSystem from which the target codes in the Map are drawn. Note that the target codes may be drawn from either a CodeSystem or a ValueSet, but not both. the ValueSet from which the source codes in the Map are drawn. Note that the target codes may be drawn from either a CodeSystem or a ValueSet, but not both. a URI that, when resolved, returns the known versions of the containing Map The map version associated with this catalog entry that has been assigned the CURRENT tag, if any the name by which the map is known within the context of the CTS₂ service instance. mapName must uniquely designate a single, abstract Map within the context of all maps known to the instance of the service. Note that mapName is not necessarily globally unique and the about URI should be used whenever communication information about the Map across time or service instances. A MapCatalogEntry read from a service instance. PSM A directory summarizing all or some of the MapCatalogEntries known to the service. A synopsis of a MapCatalogEntry. the CodeSystem from which the source codes in the Map are drawn the ValueSet from which the source codes in the Map are drawn the CodeSystem from which the target codes in the Map are drawn the ValueSet from which the source codes in the Map are drawn a reference to the map version with the CURRENT tag, if any the name by which the map is known within the context of the CTS₂ service instance A collection of complete MapCatalogEntry resources that meet a specified criteria. A MapCatalogEntry that meets a specified filter criteria.