Tonight I decided to take a second look at some of my stamps and found these. One British, one Denmark. What is strange is the markings on the back of the stamps. The Great Britain stamp looks almost "pre canceled" on the reverse. The Denmark stamp? I have no idea what the "3" stamp is. Any ideas on these? Please leave a comment and they get emailed to me. Thanks!**I think I've identified the marks on the Great Britain stamp. "Training Stamps" were marked with black lines to ensure they don't get used for postage after being used to train new postal employees. It appears this one, and the sheet it would have come from, were incorrectly marked on the back.
