:type '(repeat string))
+;;; @@ for encoded-word
+;;;
+
+(defgroup mime-header nil
+ "Header representation, specially encoded-word"
+ :group 'mime)
+
+;;; @@@ decoding
+;;;
+
+(defcustom mime-field-decoding-max-size 1000
+ "*Max size to decode header field."
+ :group 'mime-header
+ :type '(choice (integer :tag "Limit (bytes)")
+ (const :tag "Don't limit" nil)))
+
+;;; @@@ encoding
+;;;
+
+(defcustom mime-field-encoding-method-alist
+ '(("X-Nsubject" . iso-2022-jp-2)
+ ("Newsgroups" . nil)
+ ("Message-ID" . nil)
+ (t . mime)
+ )
+ "*Alist to specify field encoding method.
+Its key is field-name, value is encoding method.
+
+If method is `mime', this field will be encoded into MIME format.
+
+If method is a MIME-charset, this field will be encoded as the charset
+when it must be convert into network-code.
+
+If method is `default-mime-charset', this field will be encoded as
+variable `default-mime-charset' when it must be convert into
+network-code.
+
+If method is nil, this field will not be encoded."
+ :group 'mime-header
+ :type '(repeat (cons (choice :tag "Field"
+ (string :tag "Name")
+ (const :tag "Default" t))
+ (choice :tag "Method"
+ (const :tag "MIME conversion" mime)
+ (symbol :tag "non-MIME conversion")
+ (const :tag "no-conversion" nil)))))
+
+
;;; @ required functions
;;;