Language reference : Base architecture : Map elements : Map group elements
   
Map group elements
 
anchorref
keydef
mapref
topicgroup
topichead
topicset
topicsetref
The map group domain elements define, group, or reference content. Many of the map group elements are convenience elements, which means that they simply make it easier for an author to make use of existing functions.
For example, the <topichead> element allows a map to specify a heading without allowing a reference to a topic. While a <topicref> element may accomplish the same thing by creating a title and leaving off the href attribute, the <topichead> element simply makes the intent clearer and prevents the accidental inclusion of an href attribute.