A 6' post lamp is being installed at duplex town house that includes a 15 Amp single receptacle just under the the fixture near the top of the pole.

Does this receptacle require a weather proof while-in-use cover?

It is my understanding that any 15 or 20 amp 120 V receptacle installed in a wet location requires a weather proof while-in-use cover.

Is there any reason why this receptacle or any other light pole mounted receptacle would be exempt from this rule?

If so why?

If not, how can these poles be sold?