Each entity has <concept>representation-type</concept>. It must be
specified when an entity is created. <cf node="Entity Creation">
<p>
-\e$BA0@a$^$G$K=R$Y$FMh$?\e(B entity \e$B$KBP$9$k=hM}$O!"\e(Bentity \e$B$KBP$7$F$=$N=hM}$r0M\e(B
-\e$BMj$9$k$3$H$K$h$C$F<B8=$5$l$F$$$^$9!#\e(BEntity \e$B$O<+J,$N\e(B
-representation-type \e$B$rCN$C$F$*$j!"$=$N\e(B representation-type \e$B$K1~$8$F<B:]\e(B
-\e$B$N=hM}$r9T$&4X?t$r8F$S=P$7$^$9!#$3$N$h$&$J4X?t$r\e(B <concept>entity \e$B=hM}\e(B
-method</concept> \e$B$H8F$S$^$9!#$^$?!"\e(Brepresentation-type \e$BKh$K$3$N$h$&$J4X\e(B
-\e$B?t$r$^$H$a$?$b$N$r\e(B <concept>mm-backend</concept> \e$B$H8F$S$^$9!#\e(B
+Functions about entity are implemented by request processing to the
+entity. Each entity knows its representation-type. Each entity calls
+processing function corresponding with the representation-type. Such
+kind of function is called <concept>entity processing
+method</concept>. A module, consists of them corresponding with a
+representation-type, is called <concept>mm-backend</concept>.
<p>
-mm-backend \e$B$O\e(B representation-type \e$B$NL>A0$N@hF,$K\e(B <code>mm</code> \e$B$H$$$&\e(B
-\e$B@\F,<-$rIU$1$?4X?tL>$+$i$J$k\e(B module \e$B$G!"$=$N\e(B module \e$BL>$OF1MM$K\e(B
-representation-type \e$B$NL>A0$N@hF,$K\e(B <code>mm</code> \e$B$rIU$1$?$b$N$K$J$C$F\e(B
-\e$B$$$^$9!#$3$N\e(B module \e$B$O\e(B representation-type \e$B$N\e(B entity \e$B$,:G=i$K@8@.$5$l$k\e(B
-\e$B;~$K<+F0E*$K\e(B require \e$B$5$l$^$9!#\e(B
+Module name of each mm-backend consists of the prefix <code>mm</code>
+and its representation-type. The module is required automatically
+when its entity is created at first.
<h3> Message-passing for entity
<defun name="mime-entity-send">
<args> entity message <rest> args
<p>
-<var>entity</var> \e$B$K\e(B <var>message</var> \e$B$rAw$k!#\e(B
+Send <var>message</var> to <var>entity</var> with <var>args</var>, and
+return the result.
<p>
-<var>args</var> \e$B$O\e(B <var>message</var> \e$B$N0z?t$G$"$k!#\e(B
+<var>args</var> is arguments of the <var>message</var>.
</defun>
<h3> How to make mm-backend
<node> mm-backend module
<p>
-\e$B!J$9$_$^$;$s!#$=$N$&$A=q$-$^$9\e(B (^_^;\e$B!K\e(B
+(It is not written yet, sorry. (^_^;)
<p>
-\e$B!J$H$j$"$($:!"\e(Bmm*.el \e$B$r;29M$K$7$F$/$@$5$$!K\e(B
+(Please read mm*.el)
<h1> Information of Content-Type field