W-2 Box 14 is used for informational purposes. Employers use this box to report certain deductions that do not qualify to go under any other category. This usually does not have any impact on your Tax Return. You should contact your employer for a detailed explanation of what these deductions are, and what each of them mean. If you don't know the category you can select "Other (not classified)" from the dropdown.
What is box 14 on my W-2 for?