User's Guide
Address Book
Registering a frequently used destination on this machine will save you the trouble of having to enter it each time you send data. A destination registered on this machine is called an "Address Book".
You can register up to 2000 one-touch destinations in the address book. The destination types that can be registered are E-mail address, computer name, etc. depending on the transmission mode.
The Hard Disk is optional in some areas. If the Hard Disk is not installed, up to 1000 destinations can be registered in the address book.
Select whether to allow the user to register or change destinations (default: [Allow]). For details, refer to Here.