> 1) I think it makes sense to relax the syntax by making <hex float
suffix> optional. This would allow conforming implementations to read
"fixed" hexadecimal syntax used by some implementations, e.g. Chez
Scheme. The dot is still present to distinguish the output from an exact
integer.

I have incorporated this in the next draft.

 > 2) while (write-hexadecimal-float z [port]) may guarantee that the
output format fully conforms to C99/IEEE 754 notation with leading 1 and
explicit exponent, (number->string z 16) may be allowed to produce any
mathematically correct representation, including ones that start with
any hex digit and have a dot but no exponent. This would make Chez
Scheme's  number->string conforming to this SRFI:

This is an allowed behavior, as the SRFI does not add any requirements
to number->string.

-- Peter McGoron