Vista Tutorial - Wooly concepts? Terminating and non-terminating errors.

The more I explore PowerShell errors the less clear I seem to be about
what's what on some aspects.

I am struggling to think of a clear way to *anticipate* what will
produce a terminating or non-terminating error. Is there a reliable
way? Anyone care to offer a classification?

Also is there any clear documentation about $? and how it responds. My
understanding from something I read/heard long ago was that $? became
False from terminating errors but non-terminating errors seem to
change it to False too (at least in RC2).

And, given that one can alter the value of $ErrorAction from Stop to
Continue at will, is there really a worthwhile distinction (from the
user point of view) between terminating errors and non-terminating
errors? Or are those terms the best ones?

Thoughts? Or am I the only struggling a bit for clarity on this?

Thanks

Andrew Watt MVP