I don't look at quarters very often so maybe this is probably the dumbest question of the day but I have two quarters in my pocket and there the typical initials of the designer on the front of the coin by Washington's neck. I noticed I have one coin with the initials clearly visible and another where it not clear but there's more than one set of initials. Odd??
What you are seeing are two different ODVs for the series. ODV-021 and ODV-022. Here's a link: http://varietyvista.com/09b WQ Vol 2/Obverse Design Varieties.htm