CIDR question

Hi, A recent posting on comp.dcom.cisco suggested that you can't have a 7-bit subnet. For example, 192.239.0.0 255.255.254.0 should be equal to two class C networks, but the two "subnets" would be the all zeros and the all ones subnets. Apparently this goes against the Host Requirments RFC. Would this be a vaild CIDR route? Thanks.... Erik