RJ-45 style communications jacks include a housing having a plug receiving cavity that is defined, at least in part, by opposed upper and lower surfaces. A first guide protrudes from the upper surface into the plug receiving cavity. A first channel is formed in the lower surface. The width of this first channel is greater than the width of a housing of an RJ-11 style communications plug but less than a width of a housing of an RJ-45 style communications plug. Moreover, the length of the first channel is sufficient to allow the RJ-11 style communications plug to be fully inserted within the plug receiving cavity.