You posted it in that other post, about 4 down from this one right now, also titled undercabinet lights.

I don't know what you mean by 'through the back lip of (under) cabinet', but if you mean you run it out of the wall, staple it to the bottom of the cabinet, and then into the fixture using an appropriate connector, then yes, that is what is done normally.

Thanks - Thats exactly what I meant - I refered to the lip as the botton of sides that run around the perimeter. My concern was the small amount of exposed romex that is stapled under cabinet and exposed.