Resources located at URIs returned in the href attribute of "Link" specializations (e.g., EndDeviceListLink, SelfDeviceLink) SHALL conform to the schema definition for that object, which is the tag name with the “Link” suffix removed. For example, the resource at SelfDeviceLink href follows the definition for the SelfDevice resource.
If a client PUTs or POSTs a resource to a server containing attributes or elements that instead are to be populated by the server (e.g., href), the server SHALL return an HTTP 400 error.
If a function set is not implemented, Link elements to resources in that function set SHALL NOT be included.