How do you line an L5-20R? Which terminal is hot, neutral and ground?

Which terminal is hot, neutral and ground?
Creating an attic access panel?
Answers:    L5-20R:
The large curverd prong is the Ground.
Looking at the frontage of the receptacle,
The Line prong is counterclockwise from it.
the Neutral prong is clockwise.
The screws on the receptacle should be coded:
Grn. = Gnd., Wht. (Silver) = Neutr., Brass = Line.
How do i replace a gas insert fireplace...
I've looked on several web sites and I'd own to plug it into the wall and get a reading on it before I wired it. The net sites aren't very informative. I would image the sides are black and white, and the bottom is ground, but would own to see what the inside looked like. It should have duplicate convention as an outlet or any other electrical. The light colored is the white wire, the night screw is the black wire and the green is ground. Can't miss if you see that.