The "Sator Square" is one of the oldest pieces of alphanumeric spellwork we have from the ancient world. It has been discovered in Pompeii, as well as up to modern times in the Americas and even appearing in a track by German Pagan Band, Heilung. It is held to be a charm against ill luck, dog bites, rabies, insanity, childbirth pain and as a method of changing the winds. It is even referenced as a town square in Terry Pratchett's Ankh-Morpork.
Wear a little bit of magic today with Grumpy Old Crone's Sator Square T-shirt!