If I install 120v receptacles on the outside of a building, an open porch (wet location), does the recptacle have to be WR type rated?

The answer is yes. Any 15A or 20A, 125v receptacle installed in a wet location must be of the WR type. I am a state electrical inspector and was just learning to use this feature.

The answer is no.

An open porch would not be considered a wet location. An open porch would be considered a damp location.

“shall have an enclosure that is weather proof when the receptacle is covered (attachment plug cap not inserted and receptacle covers closed).

HK, read Section 406.8 (A) of the 2008 NEC, any receptacle in wet OR damp location shall be rated weather resistant.

TK's point is important.

Not everyone is under the 2008 NEC, and some have exceptions not requiring TR's.

No, Stan I was just wrong. But I do blame it on old code book. But at least I checked before I put my foot in mouth.
Going to get new code book at first chance. I don't need help from old code book to be wrong. I can do it all by myself.