+@node IDNA
+@section IDNA
+@cindex IDNA
+@cindex internationalized domain names
+@cindex non-ascii domain names
+
+Message is a @acronym{IDNA}-compliant posting agent. The user
+generally doesn't have to do anything to make the @acronym{IDNA}
+happen---Message will encode non-@acronym{ASCII} domain names in @code{From},
+@code{To}, and @code{Cc} headers automatically.
+
+Until @acronym{IDNA} becomes more well known, Message queries you
+whether @acronym{IDNA} encoding of the domain name really should
+occur. Some users might not be aware that domain names can contain
+non-@acronym{ASCII} now, so this gives them a safety net if they accidently
+typed a non-@acronym{ASCII} domain name.
+
+@vindex message-use-idna
+The @code{message-use-idna} variable control whether @acronym{IDNA} is
+used. If the variable is @code{nil} no @acronym{IDNA} encoding will
+ever happen, if it is set to the symbol @code{ask} the user will be
+queried (the default), and if set to @code{t} @acronym{IDNA} encoding
+happens automatically.
+
+@findex message-idna-to-ascii-rhs
+If you want to experiment with the @acronym{IDNA} encoding, you can
+invoke @kbd{M-x message-idna-to-ascii-rhs RET} in the message buffer
+to have the non-@acronym{ASCII} domain names encoded while you edit the message.
+
+Note that you must have @uref{http://www.gnu.org/software/libidn/, GNU
+Libidn} installed in order to use this functionality.
+