Map elements Map elements include the core components of DITA maps, such as the <topicref> and <reltable> elements. Basic map elementsDITA maps are built from a few core elements that are used for referencing and organizing topics. In addition, the <topicmeta> element can be used to specify metadata for the map, individual topics, or groups of topics.Subject scheme elementsSubject scheme elements are used to define sets of controlled values and taxonomic subjects, bind controlled values to attributes as enumerations, and specify relationships among taxonomic subjects.Parent topic: Element reference