What exactly do you mean by coding for a specific operator?
Any robust solution must not use specific details on variable parts of the technology (e.g. as the operator).
And please keep in mind, that you cannot rely on consictency of certain portions of the SIM data, as it may be updated any time by the MNO (mobile netowork operator) using OTA (over the air) technology communicating directly with the SIM file system via encrypted SMS. This includes access point names, preferred network lists, operator names, logos, network names, phonebook entries, etc...
Best practice would be to stick to the standards and to provide configuration files or user dialogues for obtaining preference settings on variable data.