"Service nos." what is it?

[gsmsalers]

Hi.
In Nokia 3310 phone book directory there are have function named "Service nos."
What is it? WHat is need?
Thanks

[nadger]

as the 3310 doesnt store numbers in the phone then these service numbers must be on your sim card i think.

if its what i think it is then they are the numbers for you to connect to your service providor for top ups/inquieries etc.