+Similarly, a disposition string may optionally be provided between
+\*(lq{\*(rq and \*(lq}\*(rq characters; it will be copied into the
+\*(lqContent-Disposition\*(rq header when the directive is processed.
+If a disposition string is provided that does not contain a filename
+parameter, and a filename is provided in the directive, it will be
+added to the \*(lqContent-Disposition\*(rq header. For example, the
+following directive:
+.PP
+.RS 5
+.nf
+#text/plain; charset=iso-8859-1 <>{attachment} /tmp/summary.txt
+.fi
+.RE
+.PP
+creates these message part headers:
+.PP
+.RS 5
+.nf
+Content-Type: text/plain; charset="iso-8859-1"
+Content-Disposition: attachment; filename="summary.txt"
+.fi
+.RE
+.PP