How to identify the items that have the shippable flag checked in front end but has value of ‘N’ in

How to identify the items that have the shippable flag checked in front end but has value of ‘N’ in backend. This is very strange as one would expect the flag in database also to be “Y” when it checked in front end. The change was never made to the item. It has been created in 2008 and never updated.