Does anyone understand :REHASH-THRESHOLD?

[greek@DEC-HUDSON]

I was just working on the VAX LISP hashing functions when I noticed that
the description of :REHASH-THRESHOLD has deteriorated a bit since the
Colander edition.  The silver book says that it can be an integer greater
than zero and less than the :REHASH-SIZE.  This makes no sense when you
read the description of :REHASH-SIZE.  It also says it can be a float
between zero and one.  Is this a percentage of the size or the rehash size?

- Paul