Units of measure — Good to know

• A class needs its base unit set before conversions mean anything — the base is written immediately after the class, and a class whose base is missing cannot convert. • Changing a unit's factor changes the meaning of every stored value expressed against it. Treat it as a data migration, not a settings tweak. • Two units with the same code in one workspace are refused: the code is what people type, so it has to be unambiguous.