This is a very simple principle from first appearance. The idea behind this is to attack the meridian via a pressure point in more than one location. and the further the distance between the attacks the better the results.
Thus as an example to attack BL-01 and the BL-67 would be perfect utilization of this Principle. Attack Along the Meridian is the 1st of the Novice Kyusho Jitsu Principles.