In the Interaction Framework page, under section 10.4, add a paragraph describing the Delete interaction, and the method to protect referential integrity when deleting a building block (AOE, result, specimen, activity ...)

DELETE can be performed as an atomic operation and in that case will succeed only if the resource is not referenced from elsewhere.

DELETE can also be included in a transaction Bundle, which instructs to remove the references (update to referencing resources) and then to delete the referenced resource.