[Taxacom] valid characters in scientific names?

[Dave Vieglais]

Can someone direct me to a specification indicating the range of valid 
characters that may appear in a scientific name (not including date and 
author)?  It has always been my assumption that this would be the set 
with ASCII character codes less than 128, or more specifically in the 
range 0x20 - 0x7e (space through tilde).

thanks,
   Dave V.