If you have a Sprint branded Blackberry phone (in this case a Bold 9930 running OS 7.1) that has an old phone number (MDN) on it, you may find that the number remains even after performing a Security Wipe of the data from the device. However, you can remove easily remove it with a device reset using these steps:

1. From the home screen, press the Send key.
2. Dial ##72786.
3. Tap Continue (Call ##72786)
4. You will receive a prompt: SCRTN will change to factory default value for DSS
5. Choose Continue
6. You will receive another prompt: SCRTN Successful. The device will now reset to apply the necessary changes
7. Click OK
8. The device will restart and the old phone number will have been removed.