Thank you for all your input on this problem. Adding a prefix to the scanned data and using a non-display field was my preferred method to handle this problem. I would have liked to make the prefix a symbol the user does not have access to (like a registered trademark symbol), but our scanner is limited to characters found on the keyboard.
When I presented this solution I was told that it would not be acceptable because “all the user has to do is open Notepad, scan a few parts and they would quickly learn what the prefix was they need to add”. The company is going to be calculating metrics based on what is scanned vs. what is not getting scanned and they are worried about users being able to manipulate the data in their favor. I know this ultimately is a personnel issue, but in the meantime I do need to do all I can to make sure they are not able to manipulate the system.
To get around this, the solution I have come up with is to have the scanner append 2 suffixes to the scanned data. A F18 followed by a F9 for example. If the two function keys are pressed in the correct order after the barcode ID has been entered, then this is a scanned Item. If the user keys in a barcode ID and presses Enter, it will still be processed, but the entry will be flagged as “Not Scanned” .
Hopefully the user will not be able to determine the sequence of function keys required to qualify as a “Scanned” entry.