Reusing DITA Topics in Multiple Maps

You can reuse an entire DITA topic simply by referencing it in multiple maps (or multiple locations within the same map) using one of the following procedures:

Reuse Topics Using the DITA Maps Manager

Make sure the DITA map is opened in the DITA Maps Manager.
Add a reference to an existing topic by using one of the following methods (depending on your particular situation):
1. If the topic already exists in this DITA map, do one of the following:
  - Simply drag the topic and press Ctrl (or Alt on macOS) at the new location within the map (or use the Copy and Paste contextual menu actions).
  - If the topic is the currently open document in the main editor, determine the new location in the map (in the DITA Maps Manager), right-click a parent or sibling topic, and select Append Child > Reference to the currently edited file or Insert After > Reference to the currently edited file.
2. If the topic already exists in another DITA map, do one of the following:
  - Open the other map in the DITA Maps Manager, right-click the topic, select Copy, switch back to the original DITA map in the DITA Maps Manager, determine the new location in the map, right-click a parent or sibling topic, and use one of the Paste contextual menu actions (Paste, Paste Before, or Paste After).
  - If the topic is the currently open document in the main editor, determine the new location in the map (in the DITA Maps Manager), right-click a parent or sibling topic, and select Append Child > Reference to the currently edited file or Insert After > Reference to the currently edited file.
3. If the topic exists in the project, but has not yet been added to a DITA map, do one of the following:
  - Right-click the topic in the Project Explorer view (or the file system), select Copy, switch to the DITA Maps Manager view, determine the new location in the map, right-click a parent or sibling topic, and use one of the Paste contextual menu actions (Paste, Paste Before, or Paste After).
  - If the topic is the currently open document in the main editor, determine the new location in the map (in the DITA Maps Manager), right-click a parent or sibling topic, and select Append Child > Reference to the currently edited file or Insert After > Reference to the currently edited file.
If your topic uses a key reference, set up the appropriate key definition in your map.
If you want to define relationships between topics, other than those defined in the topics themselves, you can add a relationship table to your map.
When you have finished adding topics, check that your map is complete and that all topic links and keys resolve correctly. To do this validation, click the Validate and Check for Completeness action on the toolbar in the DITA Maps Manager.

Reuse Topics Using Author Mode Editor

Open the DITA map in the Author mode editor.
Add a reference to an existing topic by dragging it from the Project Explorer view (or the file system) and dropping it in the desired location in the DITA map opened in Author mode. You can also accomplish the same thing by using the Copy and Paste contextual menu actions.
If your topic uses a key reference, set up the appropriate key definition in your map.
If you want to define relationships between topics, other than those defined in the topics themselves, you can add a relationship table to your map.
When you have finished adding topics, check that your map is complete and that all topic links and keys resolve correctly. To do this validation, click the Validate and Check for Completeness action on the toolbar in the DITA Maps Manager.

Displaying Multiple References to the Same Topics

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 current topic is referenced in the DITA map. It also includes navigation arrows that allow you to jump to the next or previous reference in the DITA Maps Manager.