The best example is a tap off of feed through lugs in a panelboard. There is no "wire" between the breaker and the tap but we all know it is OK if the rest of the tap rules are followed. The important thing about taps is the length and the protection of the conductors. Longer taps (10-25') require a smaller ratio between the line side breaker and the tap ampacity because voltage drop might not allow a short to operate it fast enough to protect the wire. Overload protection still comes from the load side breaker.
NFPA has decided if this tap is outside, we treat it like a service conductor (the disconnect/OC protection reads like 230.70) and we don't really care much about it burning up. I should read the ROP and see where that came from.
