"DI" is the usual abbreviation for Disability Insurance, typically a state program in which employers are required to participate. The PP#000-00000 is probably the employers policy or account number.
In TurboTax, enter the description from your W-2's box 14 on the first field in the row. Enter the dollar amount and select the correct tax category that goes with that description.
If you do not know the category, you can choose Other (not classified)
