The first Initial needs to fit into a single IP packet

Not sure if this needs to address IP fragmentation.

draft-ietf-quic-transport.md

@@ -3081,14 +3081,14 @@ corrupt ECN codepoints in the IP header.
 The QUIC packet size includes the QUIC header and protected payload, but not the
 UDP or IP header.
 
-Clients MUST ensure they send the first Initial packet in a UDP datagram that is
-at least 1200 bytes.  The payload of a UDP datagram carrying the Initial packet
-MUST be expanded to at least 1200 bytes, by adding PADDING frames to the Initial
-packet and/or by combining the Initial packet with a 0-RTT packet (see
-{{packet-coalesce}}).  Sending a UDP datagram of this size ensures that the
-network path supports a reasonable Maximum Transmission Unit (MTU), and helps
-reduce the amplitude of amplification attacks caused by server responses toward
-an unverified client address, see {{address-validation}}.
+Clients MUST ensure they send the first Initial packet in single IP packet.  The
+payload of a UDP datagram carrying the first Initial packet MUST be expanded to
+at least 1200 bytes, by adding PADDING frames to the Initial packet and/or by
+combining the Initial packet with a 0-RTT packet (see {{packet-coalesce}}).
+Sending a UDP datagram of this size ensures that the network path supports a
+reasonable Maximum Transmission Unit (MTU), and helps reduce the amplitude of
+amplification attacks caused by server responses toward an unverified client
+address, see {{address-validation}}.
 
 The datagram containing the first Initial packet from a client MAY exceed 1200
 bytes if the client believes that the Path Maximum Transmission Unit (PMTU)