My wife's W2 has an amount in Box 14, but no codes or descriptions associated with it.

I couldn't begin to speculate on what the Description or Code might be, hence my answer below. If you think it might be CASDI, then you will have to check with whoever prepared the W-2

You should be able to clear this up by entering "Not Provided" as the Description and "Other - not on above list" for the Code (last choice on the Code drop-down menu.