Samsung SGH-D415MSATMB - Manual (Page 143)

Network Services
140
Caller ID
You can prevent your phone number from being displayed on
the phone of the person being called.
Note: Some networks do not allow the user to change this setting.
The following options are available:
Default: the default setting provided by the network is used.
Hide Number: your number does not display on the other
person’s phone.
Send Number: your number is sent each time you make a
call.