In the UK a 1:1 measuring stick is called a rule in engineering, be it a 6" top pocket model, or a larger size, A scale rule is used to convert a scaled drawing to real world 1:1 or to produce such a drawing. The clue is in the use of the word scale, or scaled, as in scaled up or scaled down. If it is 1:1 it is not scaled. what we have here is two different usagtes on two different sides of the Atlantic.
Phil