The Master Mason was entitled to carve his MARK on specially selected keystones. His mark was a personal mark which was unique to him. His lesser masons would eventually be Tested and permitted to make their Mark. Freemasonry uses the model of a Guild, including the Stonemason's Guild as told in the Legend of Hiram Abiff, the Master Mason who was murdered by his false apprentices. It is all symbolic, it's meant to imbue the non stonemason with the virtues and moral and ethical code as a way to conduct themselves in their daily dealings with others. However, The Gentry and Royalty took control over the movement ... probably why Ordinary persons are not interested in joining these days. Why would you join an organisation which recruited the top echelon only from the Great but not so Good. So, Apprentice to Mason, then Master Mason and once with a Mark, a Mark Master Mason. Then within a Lodge there is a hierarchy up to Master of the Lodge, then Provincial and Grand. Without holding high office it is still possible to progress through the various degrees through the Royal Arch to the Knights Templars, but there are many side orders. It is not a Secret Society but a Society with Secrets.