+.BR json
+Produces JSON output containing headers for a reply message and the
+contents of the original message. This output can be used by a client
+to create a reply message intelligently.
+.TP
+.BR sexp
+Produces S-Expression output containing headers for a reply message and
+the contents of the original message. This output can be used by a client
+to create a reply message intelligently.
+.TP