Ricoh Aficio MP 1600 General Settings Manual page 176

Registering Addresses and Users for Facsimile/Scanner Functions
C
Select [Register as] using {U} or {T}, and then press the {OK} key.
D
Select [Sender Only] using {U} or {T}, and then press the {OK} key.
E
Press [End].
Reference
p.145 "Registering a User Code"
Changing a fax number
A
Enter the new fax number using the number keys, and then press the {OK}
key.
7
Programming the SUB Code
A
Press [Option].
B
Select [SUB Code] using {U} or {T}, and then press the {OK} key.
168