A 'Return Type' construct can be added to a 'Block Definition Diagram' via drag-and-drop. An 'Operation' must first be added to a 'Block' in the diagram before this construct can be added.
Within a 'Block Definition Diagram,' click the 'Return Type (Input/Output)' icon in the 'New' tab of the left sidebar and continue to hold down the left mouse button.
Drag the 'Return Type (Input/Output)' icon over to the bottom section of the 'Block' of the destination 'Operation' of your choice.
When the 'Operation' box highlights green, release the left mouse button to drop the new 'Return Type' and add it to the diagram.
Notice the 'Return Type' stays selected once it has been dropped. Since it is selected, the toolbar changes to include buttons for functions which can be used on the construct. The sidebar also changes to include additional 'Metadata,' 'Attributes,' and 'Relationships' tabs.
Once added to the diagram, you can specify the unit(s) for your 'Return Type' under the 'Attributes' tab of the left sidebar.
Click the 'Save' button located on the toolbar to persist your changes to your project's database.
* Note: The above process describes using the 'New' tab of the left sidebar, which automatically generates a new entity to represent each new diagram construct. If you would like to reuse existing entities from your database to represent a new construct, use the 'Existing' tab instead.
For more information on this construct and how it is represented in the database model, see Block Definition Diagram Constructs.