Why flank speed means more than full speed

What does the naval order flank speed mean, and do other navies use an equivalent?

It is mainly American terminology for pushing machinery beyond ordinary full speed, while Royal Navy practice would more likely call for maximum revolutions and all valves open.

Flank speed denotes an emergency or maximum effort beyond routine full speed, historically associated with fast forces moving around an enemy's flank. Other navies may use different words, but their engineers understand equivalent orders such as maximum revolutions with all valves open.