In Particle Flow, adding a Find Target test or a Speed By Icon operator to a particle system creates a special viewport icon used by the action. This icon is known as an operator icon. In the 3ds Max scene, an operator icon functions as a Helper object, and, in fact, you can also add these two actions from the Create panel by choosing Helpers 
Particle Flow.
Find Target icon (top); Speed By Icon icon (bottom)
Find Target icon (top); Speed By Icon icon (bottom)