Section: 5.1.3.2.2 5GS update status in the UE
Content: In order to describe the detailed UE behaviour, the 5GS update (5U) status pertaining to a specific subscriber is defined. If the UE is not operating in SNPN access operation mode (see 3GPP TS 23.501[ System architecture for the 5G System (5GS) ]  [8]), the 5GS update status is stored in a non-volatile memory in the USIM if the corresponding file is present in the USIM, else in the non-volatile memory in the ME, as described in annex C. If the UE is operating in SNPN access operation mode, the 5GS update status for each SNPN whose SNPN identity is included in the "list of subscriber data" configured in the ME (see 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [5]) is stored in the non-volatile memory in the ME as described in annex C. The 5GS update status value is changed only after the execution of a registration, network-initiated de-registration, 5GS based primary authentication and key agreement, service request, paging procedure or due to change in the current TAI which does not belong to the current registration area while T3346 is running. 5U1: UPDATED The last registration attempt was successful. 5U2: NOT UPDATED The last registration or service request attempt failed procedurally, e.g. no response or reject message was received from the AMF. 5U3: ROAMING NOT ALLOWED The last registration, service request, or registration for mobility or periodic registration update attempt was correctly performed, but the answer from the AMF was negative (because of roaming or subscription restrictions).