Is it the two letters (?) printed over the head of Hermes? Looks like OD or 0D or something like that..
Very good Sarah, they are the wrong way round it should be overprinted as 10 not as 01, it is know as the Zante error and is rather rare so off you go your turn
Well, we have had a bunch of tough ones, so I figured I'd put up an easy one for a change But now I'm sure you'll up the ante with a hard one, Tu.
http://timbrolog.blogspot.co.uk/ What is wrong with this First Day Cover? Click on the image to enlarge it and it is quite easy then.
The ink printing the car name and queens head is faded or improperly printed on the middle and far-left stamps.