Section: 9.4.1.1 Old P-TMSI signature
Content: The MS shall include this IE, if the MS holds a valid P-TMSI, P-TMSI signature and RAI, or if the TIN indicates "GUTI" and the MS holds a valid GUTI, or if the TIN is deleted and the MS holds a valid GUTI, but no valid P-TMSI and RAI. If the MS is configured for "AttachWithIMSI" as specified in 3GPP TS 24.368[ Non-Access Stratum (NAS) configuration Management Object (MO) ]  [135] or 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [112] and is attaching in a new PLMN which is neither the registered PLMN nor in the list of equivalent PLMNs, the MS shall not include this IE.