They specify different things. The wire side of a bulkhead connector may be male or female. Some connectors (i.e. the Molex ones you used to see at Radio Shack)

They specify different things. The wire side of a bulkhead connector may be male or female. Some connectors (i.e. the Molex ones you used to see at Radio Shack) are even designed so you can make a custom arrangement of male/female contacts within one connector housing.