Describe limitations of quic_enforce_single_packet_chlo flag
PiperOrigin-RevId: 429174918
diff --git a/quic/core/quic_protocol_flags_list.h b/quic/core/quic_protocol_flags_list.h
index 3e32713..42b6c9e 100644
--- a/quic/core/quic_protocol_flags_list.h
+++ b/quic/core/quic_protocol_flags_list.h
@@ -22,10 +22,13 @@
false,
"If true, disable pacing in QUIC")
-QUIC_PROTOCOL_FLAG(bool,
- quic_enforce_single_packet_chlo,
- true,
- "If true, enforce that QUIC CHLOs fit in one packet")
+// Note that single-packet CHLOs are only enforced for Google QUIC versions that
+// do not use CRYPTO frames. This currently means only Q043 and Q046. All other
+// versions of QUIC (both Google QUIC and IETF) allow multi-packet CHLOs
+// regardless of the value of this flag.
+QUIC_PROTOCOL_FLAG(bool, quic_enforce_single_packet_chlo, true,
+ "If true, enforce that sent QUIC CHLOs fit in one packet. "
+ "Only applies to Q043 and Q046.")
// Currently, this number is quite conservative. At a hypothetical 1000 qps,
// this means that the longest time-wait list we should see is:
