I found this code on this site (I've modified),
If Column A is duplicated, delete only the rows with the word "No Constraint" in Column 13.
See attached file, the rows highlighted are the ones that should be deleted.
Application.ScreenUpdating = False
RowsA = Cells(Rows.Count, 1).End(xlUp).Row
For i = 1 To RowsA
Val1 = Cells(i, 2)
For J = i + 1 To RowsA
Val2 = Cells(J, 2)
If Val1 = Val2 And Cells(i, 13) = "No Constraints" Then
Application.ScreenUpdating = True