To turn on and setup 'behavior linking' in client documents...
Navigate to the Client Management section of the Configuration Reference Libraries (System > Settings & Security > Configuration > Reference Libraries).
Click on Client Document Types.
Click Add New, to add a new Behavior Support Plan (BSP) Document Type.
Make sure the Link Behaviors box is checked and the Document is Active.
Click Save to save your new Client Document Type.
Once the behavior linking is enabled, it appears on the corresponding client document type.
