You must pass either a content_id or a content_type.

The response results is just an integer representing the number database rows deleted. If no database rows are found 0 is returned. In such cases the call is still successful, it just that the params passed in did not have a match.

Note that is a PATCH method, even though it deletes a row in the content-permission database table. This is because we're interacting with the Permissions' assignments by their defining properties—rather than interacting with the more abstract connections (the ContentPermission table entries) by their ids.