Fully implemented:
AT Command> INFO: Parser interpreted command AT+CGSN
AT Command> INFO: Parser interpreted command AT+CGMM
AT Command> INFO: Parser interpreted command AT+CGMI
AT Command> INFO: Parser interpreted command AT+CPIN?
AT Command> INFO: Parser interpreted command ATE0Q0V1+CMEE=1
AT Command> INFO: Parser interpreted command AT+CFUN?
AT Command> INFO: Parser interpreted command AT+CFUN=1
AT Command> INFO: Parser interpreted command AT+CIMI
AT Command> INFO: Parser interpreted command AT+COPS?
AT Command> ERROR: Parser rejected command AT+CREG
AT Command> INFO: Parser interpreted command AT+CGACT=1,1
AT Command> INFO: Parser interpreted command AT+CGDCONT?

Not implemented:
AT Command> ERROR: Parser rejected command AT+CNUM
AT Command> ERROR: Parser rejected command AT+CRSM
AT Command> ERROR: Parser rejected command AT+CGMR
AT Command> ERROR: Parser rejected command AT+CESQ
AT Command> ERROR: Parser rejected command AT+CNTI
AT Command> ERROR: Parser rejected command AT!BAND?
AT Command> ERROR: Parser rejected command AT+PACSP?