I don't know what it means, but SE is flat with 2 hots and a bare neutral (wrapped around the hots). SER has two hots, an insulated neutral and a reduced ground, and is round in shape, and the conductors are twisted together. Does R stand for "round" (that's how I remember it)
[This message has been edited by sparky66wv (edited 05-18-2001).]
