|DITA map files|
Any topics referenced anywhere in the ditamap will be processed into the output publication.
Topics to be included in the output are referenced through topicref elements in the ditamap. The topicref elements (and specialisations of topicref) are used both in the hierarchy and the relationship table sections of the map. If a ditamap includes an embedded map (a topicref referencing a ditamap rather than a DITA topic), then topics referenced by topicref elements in the embedded map will also be included in the output.
Simplistically, any topic referenced in the ditamap will be included in the output. An exception is for topics with the topicref element's print attribute set to no; these topics will not be included in page layout outputs (such as PDF).