JohnB5677 has it right with, possibly, one clarification. VA allows you to exclude interest and dividends on both United States and Virginia obligations from your state taxable income. (https://law.lis.virginia.gov/admincode/title23/agency10/chapter110/section142/)
Your actual 1099-DIV provides the requisite information about United States interest and dividends, but does not have a field for state obligations. That would appear in that Supplemental information. (It also typically is provided as a percentage of your dividend on a mutual funds website in their tax area, though it can take some digging.)
