Section: 7.6.4.1 IEIs unknown in the Type 6 IE container information element
Content: The UE shall ignore all IEs with an IEI unknown in a Type 6 IE container information element which are not encoded as "comprehension required" (see 3GPP TS 24.007[ Mobile radio interface signalling layer 3; General Aspects ]  [11]). The network shall take the same approach. NOTE: The set of IEIs defined for a Type 6 IE container information element is independent of the set of IEIs defined for other parts of the message. Therefore, an IE can be unknown in a Type 6 IE container information element, even if an IE with the same IEI is known in other parts of the message, and vice versa.