|DITA map files|
The technique of using embedded, or nested, ditamaps can make it easier to manage documents by separating complex collections of topics into a number of smaller, simpler collections.
The topicref elements in a ditamap usually reference a topic. However, they can also reference ditamaps, which opens up the opportunity for having embedded (or nested) maps.
<topicref format="ditamap" href="engine/ej25.ditamap" navtitle="2.5 Litre Engine"> </topicref>
Re-used, embedded (or nested) ditamaps
Nesting ditamaps is a useful tool in permitting content re-use and authoring efficiency.
The term mapref is sometimes used as shorthand for a topicref with a format attribute of ditamap. Until DITA 1.2, there was no DITA element of mapref, but 1.2 introduced a mapref as a convenience element identical in functionality to topicref with a format attribute of ditamap.