His method abbreviates phases with letters and uses symbols and numbers to represent processes and sizes of molecules, respectively. For example, you write the shorthand for aioli sauce, a mayonnaise-like emulsion ofolive oilflavored with lemon juice and garlic, as: O[10-5, 10-4] ÷ W[d ...
There are a lot of potential variations, but what I’ve listed should allow you to get your board manufactured just about anywhere. Industry convention says that it should always be in one file. I have heard of some manufacturers asking for one BOM for the parts on top and a second for ...