In a recent answer about GM-ming in D&D, I had to resort to Rule 0, upon which doppelgreener did correctly point out that it is not universal about all games but the core of D&D mentality. In the chat then kviiri did point out that "The GM is always right" is actually a pretty crap rule on itself.

Now I wonder: Where and when did the rule 0 actually got codified as we know it now?

I have the faint feeling that it might have come from the origins of Pen and Paper in wargaming, where it was the job of a judge to decide "this is what the rules mean, this is how it is to be interpreted, but I can't put my finger on it more precisely.

This is NOT about when the GM is asked to improvise or to handle something akin to his own Fiat, it is about where the "Rule 0" was first mentioned in a print product explicitly. It has been in various variants since then. Some examples of this:

The Guide [...]They also have the final call on rules disputes and typically control what stays and what goes if something seems out of line.^{Hc Svnt Dracones, p5}

The GM Rules - This is not a democracy. The GM is the boss. You should feel free to ask questions, but when a ruling is made, accept it.^{Sengoku Revised Edition, p7}