Star codes and USSD strings beginning with asterisks—such as combinations featuring 120 and 001—typically function as administrative network commands, diagnostic shortcuts, or specialized service activation strings designated by mobile telecommunications operators. Subscribers frequently dial these keypad sequences to interact directly with automated cellular server platforms, enabling actions such as checking prepaid SIM card balances, transferring mobile credit, accessing customer support portals, or configuring specific network routing preferences. The exact function depends entirely on the proprietary programming of the regional mobile network operator issuing the code.