Samsung DS-5012L - Manual (Page 147)

Navigation Menus DS/ITP-5012L Phone User Guide
134
3.
When the ‘Are you sure you want to permanently delete your data?’
message appears, select [Yes] and press the [Enter] button.
All the telephone numbers saved in the Phone Book will be deleted.
z
Recent caller/called numbers are not deleted.
Checking Your Own Extension
Number
You can check your own extension number if you need to.
Press the [Menu] button and use the direction buttons to select
Æ [7. My own number]
Then, press the [Enter] button.
Your number is displayed.