For a meet-point cutting procedure, it’s often much simpler if you can generate a preform to establish the girdle outline first. The CAM (Center-point Angle Method) is a way of doing that. There’s a good explanation of this, as well as OMNI and CLAM methods, in volume 2 of Tom Herbst’s “Amateur Gemstone Faceting”.
Other abbreviations on a gem design refer to the geometry of the finished stone, in terms of ratios. L is length, W is width, C is crown height, P is pavilion depth, etc.