I have just come across, protected in plastic, a fiver I kept from a few years back: it has Elizabeth Fry on the back. I kept it because there was something odd about it but, for the life of me, I can't remember what the oddity was. There's no question of its being valuable: the fault was widely publicised and thousands of people must have kept one. Can anyone remember what was different about it?
It may be one of the new issue a few years back that had to be withdrawn. They were made with a new plastic technique and as jenstar says, when numbered the ink did not adhere properly and could be rubbed off easily.