is 5 digits "CCCOO", where CCC is 3-digit country code, and OO is 2-digits operator's code. For example: "23433" = "Orange UK". See Wikipidea for country and network codes. To show operator name based on the SIM card used (eg. for cases where dual SIM adapter used), set HKLM\SOFTWARE\OEM\PhoneSetting\ONSDisplayRule=1 (DWORD decimal)