Files are named according to ScanSnap Manager settings.
There are 4 ways in which you can specify a file name:
[yyyy_MM_dd_HH_mm_ss]
Date and time; year/month/day/hour/minute/second
e.g.) 2014_02_26_17_01_43.pdf
[yyyy-MM-dd-HH-mm-ss]
Date and time; year/month/day/hour/minute/second
e.g.) 2014-02-26-17-01-43.pdf
[yyyyMMddHHmmss]
Date and time; year/month/day/hour/minute/second
e.g.) 20140226170143.pdf
[Custom File Name]
Give it a file name of your own; a name containing letters as well as numbers of 1-6 digits may be selected.
e.g.) Scan001.pdf