Operator name in handset.

Hi all,
when doing manual network search in handset, the handset can display list of operator's name, and this name list sometime is not properly displayed, the network code (broadcasted by the network) is show instead.

Can anyone help me to explain the mechanism of this phenomenon? Is the "network-code" hard written and mapped to the Operator's name during the handset being made. if yes, where do mobile manufacturers take this mapping information from ( from AA.14 submitted by operators to GSMA?)