Hi Charu,
If I am not mistaken you can use the id locations to program say serial numbers of your product. So under IC-pROG just put a value and program you should be able to see a different ID. For serialized quick turn programming you can use winpic800 that automatically increments your id while batch programming.
9.9 ID Locations
Four memory locations (2000h-2003h) are designated
as ID locations where the user can store checksum or
other code identification numbers. These locations are
not accessible during normal execution but are
readable and writable during Program/Verify. Only the
Least Significant 7 bits of the ID locations are used.
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