The term was originally conceived by Sir Arthur Percival Heywood who used it in 1874 to describe the principle behind his Duffield Bank Railway, specifically its gauge, distinguishing it from a "Narrow Gauge" railway.
A general aspect about minimum-gauge railways is that the loading gauge is maximized, which is to say the dimension of the equipment is made as large as possible with respect to the track gauge, while still providing enough stability to keep it from tipping over.