This one, on an F16, has always intrigued me. Ghosting of Victoria's face can be seen (as it often does) above Britannia's left knee, but there is also something strange going on with the border teeth.
The series of pictures at the bottom show an overlay picture of border teeth, from the same coin, which I have made gradually transparent from 0% to 100% as go from left to right hand side. This shows that the marks through Britannia's knees are clearly from border teeth.
I bought this coin at Heritage in 2013 (MS63 Slabbed), and it took me a long time to find another F16 like this, to prove that it must have occurred during the minting process.......rather than the coin being hit with something post-minting.
I will show the pictures of that other coin immediately below, as this picture uses up my 500Kb allowance!!