M
Set up call diverts using MMI Supplementary codes without having to remember the codes. As these are MMI codes and not actually ussd codes, they should work the same for most GSM networks.
To avoid erasing useful default diverts, be sure to check the status before changing it.
Call Waiting
When active, your phone will notify if you receive a call while you are already on another call, allowing you to put one on hold and answer the second call.