BCD Value Character/Meaning
'0' "0"
... ...
'9' "9"
'A' "*"
'B' "#"
'C' DTMF Control digit separator (GSM 02.07 [3])
'D' "Wild" value This will cause the MMI to prompt the user for a single digit (see GSM 02.07 [3]).
'E' Expansion digit ("Shift Key").
It has the effect of adding '10' to the following digit. The following BCD digit
will hence be interpreted in the range of '10'-'1E'. The purpose of digits in
this range is for further study.
'F' Endmark e.g. in case of an odd number of digits