Sharp FO-4400 - Manual (Page 18)

Connections
16
Verification Stamp option
Note: This feature is available as an option. Consult your dealer if you wish to
use this feature.
When transmitting a document, you can have the fax machine stamp each
document page as it is scanned. After scanning, you can check to see if all
documents have been stamped to verify that no double feeds occurred. (A
double feed occurs when two pages are fed through the scanner at once,
which means that one of the pages is not scanned.)
To use this function, have your dealer install the Verification Stamp option, and
then set Option Setting 29 to ON as explained on page 109.