And 14a (or 15a, or 16a) on a form 1099-R...in the "Software" questions, just refers to the first state line for boxes 14,15,16 on a 1099-R form. Some people move states during the year, and then they will have state withholding for two states.
Thus the software will sometimes refer to boxes:
14a,15a,16a for one state
and
14b,15b,16b for the second state.