Corner Letters On Great Britian Stamps??

It's probably been talked about already but I did a search and found nothing with what I used. My question is what are the corner letters on the early stamps used for. I imagine it must be there arrangement on the sheet. Would it be HJ/JK/KD on the sheet or something different.

They are known as check letters, and they were placed there for two reasons: Firstly they identified the position on the plate. Secondly, it was an anti-fraud measure. There was some concern that if only part of a stamp were cancelled, someone could take uncancelled parts of two stamps and join them together and thus defraud the post office of revenue. If the check letters didn't match up, then it would be a tipoff that that someone had done just that.

This illustrates it attractively

http://philatelics.org/~allan/shrop...heet10r.html

You're correct to say the letters are for marking placement on the pane.

Here are just a couple of sites to explain.


http://philatelics.org/~allan/shrop...s/page1.html

http://www.stamp-shop.com/penny-black.html


There are more explanation sites, as well as more info available on this site and from SCF members.