When you are working in DITA, there are several approaches that you can use to create topics and maps. You can start by first creating topics and then assembling your finished topics into one or more documents by creating one or more maps, or you can start by creating a map and then adding new topics to it as you work.
The topics-first approach is generally more appropriate if you intend to do a lot of content reuse, as it encourages you to think of each topic as an independent unit that can be combined with other topics in various ways. The map-first approach will be more familiar to you if you are used to creating books or manuals as a whole. Oxygen XML Author Eclipse plugin supports both approaches.
A DITA map organizes content hierarchically, so you can add a topic as a child of the map root element or as a child or sibling of any item already in the map. Therefore, the first step to adding a topic to a map is always to choose the place it will be inserted into the map.
At the XML-level, a topic is added to a map by adding a reference to the map that points to
the topic. There are a variety of reference types that you can use. The default type is the
<topicref> element. See the DITA documentation for the full range of reference
elements and their uses. Oxygen XML Author Eclipse plugin provides several tools for inserting
reference elements into a map:
Insert
Reference button from the DITA Maps
Manager toolbar.
Insert Reference from the DITA Maps
menu.Step Result: The new topic is now referenced (as a
<topicref>) in the DITA map at the location where
you inserted it and the new topic is opened in the editor.
Oxygen XML Author Eclipse plugin includes a feature in the DITA Maps Manager that allows you to quickly create multiple skeleton topics at once and you can specify their hierarchical structure within the DITA map.
To access this feature, right-click a node in the DITA Maps Manager where you want the new topics to be inserted and select Fast Create Topics. This opens the Fast Create Topics dialog box where you can configure the structure for the new topics.
For more information, see Fast Create Multiple DITA Topics.
Oxygen XML Author Eclipse plugin allows you to reuse entire topics by adding multiple references to the same topic in a DITA map. Whenever multiple references to the same topic are detected in the context of the current map in the DITA Maps Manager, an indicator will appear in the top-right corner of the Author mode editor that shows the number of times the topic is referenced in the DITA map. It also includes navigation arrows that allow you to jump to the next or previous reference.

Delete button on the DITA Maps
Manager extended toolbar.