Charsets on Debian

["Scott Bronson" <bronson@rinspin.com>]

I recognize that on my US Debian system, characters 0-127 are
simply ASCII, and that characters 160-255 are ISO-8859-1.
 
What standard covers characters 128-159?   

Also, how do I change my charset?  Wouldn't it be better if the
Debian X packages used ISO-8859-15 by default?

Thank you,

   - Scott