Box 13 of a 1099-DIV form????
Box 13 of that form indicates the sub-portion of box 12 $$ that came from "Private Activity" bonds. Those are bonds for some things, like a City's Professional athletics stadium. Those $$ do become taxable in some situations.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
