= Ideas for a RFC 6532 API =

== Policy ==
 - the internal charset has to be changeable (or at least a USASCII/UTF8 switch is needed)

== Header ==

=== _header_value_parser ===

 - use settings from policy in _fold

== Steps ==

 1. change the Header class in header.py to make the default charset changeable (add '_internal_charset' property)
 2. NOT SURE ABOUT THIS: create new classes in the headerregistry.py (e.g. UnicodeAddressHeader as inheritor of AddressHeader
 3. provide an alternative header map (e.g. _unicode_header_map) using the new classes
 4. HeaderRegistry: create an inherited class with the _unicode_header_map as default.

...

 5. create a policy making use of the above