Update baggage.md

content/en/docs/concepts/signals/baggage.md

@@ -82,7 +82,9 @@ services, it is not a replacement for programmatic data flow. Because baggage is
 stored in HTTP headers, not only does this mean the data is available for anyone
 who can read those headers to consume, but it would be a poor choice to
 propagate general program data given the practical limits HTTP servers place on
-header lengths.
+header lengths. Furthermore, clients reserve the right to drop HTTP headers,
+which would result in unexpected data loss. To reiterate: don't use baggage
+as a replacement for programmatic data flow.
 
 > For more information, see the [baggage specification][].