Fujitsu ScanSnap S1500M Operator's Manual page 343

Actions (for Mac OS Users)
When you select [PDF(*.pdf)] for [File format] in the [File option] tab of the ScanSnap
setup window, a four-digit serial number is automatically added to the name of the file
which is saved to Evernote.
e.g. When the file name is [ScanSnap], the file is saved as:
ScanSnap_0001, ScanSnap_0002, ScanSnap_0003...
The file in which the scanned image is saved remains in the folder specified for [Image
saving folder] in the [Save] tab of the ScanSnap setup window even after the scanned
image is saved to Evernote. Delete this file if unnecessary.
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