Connector assembly having compact keying and latching system

Connector assembly comprises plug housing and receptacle housing. The plug housing has a latch arm hinged to one of its sidewalls having a forward portion which extends towards the mating end. A plurality of removable keys are mounted on the plug housing adjacent to the forward portion of the latch arm. The latch arm has an inspection opening to determine the presence or absence of the keys. Keying is achieved by removing one of the keys and placing a key plug in the corresponding keyway in the receptacle. The latch arm has a rearward portion which extends towards the rearward face of the housing. Clearance slots are provided in the rearward portion for wires which extend through the clearance openings, through wire-admitting slots in the housing sidewall and to terminals in the housing. The clearance slots permit the rearward portion of the latch arm to be depressed thereby to raise the forward portion when the plug housing is latched to, or unlatched from, the receptacle housing.