I tried this over in the world error forum but got no replies so wondered if anyone could help me over here :)
Just wondering whether anyone could shed any light on what this error is and how it happened ?


The obv error I've seen plenty times before, although never on a 50p but I'd still like to know what exactly it is (Doubled Die / Double Struck / Slipped Strike?)
But it's the reverse that's puzzling...it could be a random die chip problem leading to the extra, but, apart from the I, it seems to get progressively worse over F>Y (Plus the trident)
Thanks for any help

Edit: Just to add, there appears to be slight doubling of some of the letters (Specifically the F I F of fifty) which doesn't come across so good in the pics.