A New Internet-Draft is available from the on-line Internet-Drafts directories.
Mailbox names often represent the names of human users. Many of theseusers throughout the world have names that are not normally represented by the users with just the ASCII repertoire of characters, and would therefore like to use their real names in their mailbox names. These users are also likely to use non-ASCII text in their common names and subjects of email messages, both in what they send and what they receive. This protocol specifies how to represent all headers of email messages encoded in UTF-8.
http://www.ietf.org/internet-drafts/draft-hoffman-utf8headers-00.txt