I would like to know what is the meaning of "Arming ESC" ?
Is this compulsory for all ESC ?
Very common on Aircraft controllers.
The last thing you want is if your throttle is at full whack for the prop to spin up and chop something off...
So normally you turn on radio gear, connect battery to the esc, then move the throttle stick to the bottom, the motor beeps signalling that the esc is armed and any further stick movement will cause the motor to spin up.
As for compulsory, as far as I know it isn't, but in some applications it would be a good safety precaution 
is there anywhere that i can find a 'arming esc' tutorial or reference?