Bill,
338-1(b)states that USE is identified for underground use.
338-1(a)says nothing about underground use of SE, so I'm guessing that, by omission of the reference to underground use, it is not acceptable, even in pipe.
I'm struggling myself, with the conductors in the SE. I know they are XHHW, which is approved for wet locations, but I'm thinking maybe the uninsulated neutral (aluminum)would be trouble.
It would be nice if Art.338 had a "Uses permitted" & "Uses not permitted" sections like Articles 336 & 339.
It would greatly simplify the installation if I could re-use the SE.

[This message has been edited by Redsy (edited 09-02-2001).]