"A salient is a protrusion in a geometric figure, a line of battle, or an expanding weather front. As technological systems expand, reverse salients develop. Reverse salients are components in the system that have fallen behind or are out of phase with the others"
A reverse salient simply means that through no particular action, there is a huge demand for a particular invention. There is a portion that is out of phase. Identify and solve it. Fun stuff.