Accepting Only Encrypted Secured Printing
You can set the machine to only receive encrypted secured print jobs from computers.
This setting can be specified when the Encrypted Print Settings function is available for use. For information on the optional products required to use the Encrypted Print Settings function, see "Optional Products Required for Each Function."
1.
Press 
(Settings/Registration).
(Settings/Registration). 2.
Press [Function Settings] → [Encrypted Secure Print] → [Only Allow Encrypted Print Jobs].
3.
Press [On] → [OK].
If you do not want to restrict print jobs, press [Off].