+
+When used as an overlay, the external program should return a
+CONTINUE response if request processing should continue normally, or
+a regular RESULT response if the external program wishes to bypass the
+underlying database.
+
+If the overlay is configured to send response messages to the external
+program, they will appear as an extended RESULT message or as an
+ENTRY message, defined below. The RESULT message is similar to
+the one above, but also includes the msgid and any configured
+extensions:
+.RS
+.nf
+RESULT
+msgid: <message id>
+code: <integer>
+matched: <matched DN>
+info: <text>
+<blank line>
+.fi
+.RE
+
+Typically both the msgid and the connid will be needed to match
+a result message to a request. The ENTRY message has the form
+.RS
+.nf
+ENTRY
+msgid: <message id>
+<entry in LDIF format>
+<blank line>
+.fi
+.RE
+