The (proto) Ancient and Accepted Scottish Rite degree “Maitre Parfait” (‘perfect master’) often has a pyramid on the tracing board. Sometimes the pyramid has the letters “M B” on it, the 3rd degree word. Sometimes the letter is “L“, but I also ran into “J M B” standing for “Jacobus Molay Burgondi”, Jacques de Molay from Bourgogne.
Thuileur 1 – 333 Pascal Barbier