--- /dev/null
+These extensions can be used if `--protocol udp' is specified. It
+provides the following options:
+.TP
+[\fB!\fP] \fB--source-port\fP,\fB--sport\fP \fIport\fP[\fB:\fP\fIport\fP]
+Source port or port range specification.
+See the description of the
+.B --source-port
+option of the TCP extension for details.
+.TP
+[\fB!\fP] \fB--destination-port\fP,\fB--dport\fP \fIport\fP[\fB:\fP\fIport\fP]
+Destination port or port range specification.
+See the description of the
+.B --destination-port
+option of the TCP extension for details.