I have a huge list of 10 digit numbers in column B.
These numbers where scanned in using hand-held barcode scans, so human error
is possible.

I may have duplicates in the column, what I would like to do is somehow
identify the duplicates.

My questions a

1) Can I format the column before scanning to display a (2), (3), etc. after
a number if it is a duplicate?

2) How to format the column after scanning to identify the duplicates and
delete them.

Thank you very much.