ChangeLog: Updated the entry for tls-hs-defragmentation

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/ChangeLog.d/tls-hs-defrag-in.txt b/ChangeLog.d/tls-hs-defrag-in.txt
index 55103c9..4fd4a4e 100644
--- a/ChangeLog.d/tls-hs-defrag-in.txt
+++ b/ChangeLog.d/tls-hs-defrag-in.txt
@@ -3,3 +3,10 @@
      by the spec. Lack of support was causing handshake failures with some
      servers, especially with TLS 1.3 in practice (though both protocol
      version could be affected in principle, and both are fixed now).
+     The initial fragment for each handshake message must be at least 4 bytes.
+
+     Server-side, defragmentation of the ClientHello message is only
+     supported if the server accepts TLS 1.3 (regardless of whether the
+     ClientHello is 1.3 or 1.2). That is, servers configured (either
+     at compile time or at runtime) to only accept TLS 1.2 will
+     still fail the handshake if the ClientHello message is fragmented.