-\fB\*(PN\fR will respond with extensive information on how a packet
-in \fIflow\fR would be handled if it were received by
-\fIswitch\fR. No packet will actually be sent. Some side effects may
-occur, but MAC learning in particular will not.
+If you wish to include a packet as part of the \fBofproto/trace\fR
+operation, there are two ways to do it:
+.
+.RS
+.IP \fB\-generate\fR
+This option, added to one of the ways to specify a flow already
+described, causes Open vSwitch to internally generate a packet with
+the flow described and then to use that packet. If your goal is to
+execute side effects, then \fB\-generate\fR is the easiest way to do
+it, but \fB\-generate\fR is not a good way to fill in incomplete
+information, because it generates packets based on only the flow
+information, which means that the packets really do not have any more
+information than the flow.
+.
+.IP \fIpacket\fR
+This form supplies an explicit \fIpacket\fR as a sequence of hex
+digits. An Ethernet frame is at least 14 bytes long, so there must be
+at least 28 hex digits. Obviously, it is inconvenient to type in the
+hex digits by hand, so the \fBovs\-pcap\fR(1) and
+\fBovs\-tcpundump\fR(1) utilities provide easier ways.