Come to think of it...I had in mind a sequence of "skip" statements, that would back out of a level one at a time, until you finally reached the desired level. But, I think maybe these "skip" statements essentially play the role of what you called "positive unindent tokens" (I like that term).
I agree that simply using terms like this means indentation grammars are problematic -- or does it? One thing that bothers me is that *people* don't seem to have a great deal of difficulty with them. Why not? === Gregory Woodhouse <[EMAIL PROTECTED]> "Without the requirement of mathematical aesthetics a great many discoveries would not have been made." -- Albert Einstein