{HEAD ~ A modular electrical component} includes {TAIL ~ a mating keying arrangement} complimentary to the keying arrangement in the channel, and thereby only allows the modular electrical component to be insertable into the channel and coupled with a corresponding electrical terminal array in a preselected orientation 
includes
{ HEAD ~ A modular electrical component } includes { TAIL ~ a mating keying arrangement } complimentary to the keying arrangement in the channel , and thereby only allows the modular electrical component to be insertable into the channel and coupled with a corresponding electrical terminal array in a preselected orientation
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH