Hitachi TD61-2472 - Manual (Page 22)

3 A confirmation message is displayed. With the keys select either
"Yes" or "No".
If you select "Yes", the "Deletion complete" message is displayed
immediately, then the display returns to the contact list menu.
1.7.5 Erase all
Deleting all the data in the contact list.
1 From the contact list menu, select "4. Delete all".
2 A confirmation message is displayed. With the keys, select either
"Yes" or "No".
Hitachi Cable 18