Setting the Paper Size Group for Auto Recognition in the Paper Source

You can set which types of paper (A or B series paper or inch paper) will be detected automatically in each paper drawer.
Register the same paper size as the paper loaded in the paper drawer. If an incorrect paper size is registered, the paper size may not be detected, and a screen prompting you to confirm the setting may be displayed.
The paper sources, which can be configured in this setting, are Paper Drawers 1 to 4.

Press (Settings/Registration).
Press [Preferences] → [Paper Settings] → [Paper Size Group for Auto Recog. in Drawer].
Select the paper size group that you want to use for automatic paper size detection → press [OK].
Details of each item are shown below.
Paper Drawer:
 A/B Size, Inch Size