I could have clarified a bit more.

The problem that Footleg described when he tried to amend the example he sent (define the scraps as looking 090 deg) was because the scraps were looking to the east, but therion was trying to export non-existent scraps looking to the north. (By default therion will export just a centerline in this case, if there are no other errors).

The differentiation of elevation directions is necessary because often you may draw elevations of the cave from multiple directions (of course!).

Bruce