Ricoh Aficio MP 161SPF - Manual (Page 258)

Registering Addresses and Users for Facsimile/Scanner Functions
250
7
E
Enter the registration number you want to protect using the number keys
or the Quick Dial keys, and then press the {OK} key.
You can automatically specify registration numbers 001-016 by pressing the
Quick Dial keys.
Press [Search] to search by name, destination list, registration number, user
code, fax number, e-mail address, or folder destination.
F
Press the {OK} key.
G
Press [Details].
H
Select [Auth. Protect] using {U} or {T}, and then press the {OK} key.
I
Select [Register as] using {U} or {T}, and then press the {OK} key.