W-2 box 12 is used for a number of different things. Each entry in box 12 has a one-letter or two-letter code before the amount. The code tells you what it is. Just enter the code and amount in TurboTax as they appear on your W-2. If box 12 on your W-2 is empty, don't enter anything. Just leave it empty in TurboTax.
Box 14 can be used for just about anything that the employer wants to put there. In general there are no rules or standards for the information in box 14, or for any abbreviations that are used. However, there are a couple of standard entries for certain New Jersey employment taxes. UI/HC/WD is tax you pay for state unemployment insurance. The abbreviation that's used may vary. The TurboTax category is "New Jersey UI/WF/SWF tax."
FLI is Family Leave Insurance. It belongs in box 14, but employers often put it in the wrong place. Enter it in box 14. The TurboTax category is "New Jersey FLI tax."
