Star Note*** 1957 $1 Blue Seal Silver Certificate Grades xf. When notes are discovered that have been printed incorrectly (such as having the serial numbers upside down, etc.) the misprinted "error notes" are replaced with star notes because no two bills within a certain series can be produced with the same serial number. They are used to maintain a correct count of notes in a serial number run. By their nature, star notes are more scarce than notes with standard serial numbers and as such are widely collected by numismatists. Some of the highest prices paid for modern (post-1928) U.S. banknotes have been for star notes.