Note that ver+fmt bytes in serialized data must not be removed
@@ -9928,7 +9928,12 @@ static unsigned char ssl_serialized_session_header[] = {
* opaque session_format[2]; // version-specific 16-bit field determining
* // the format of the remaining
* // serialized data.
- * // In this version, this indicates whether
+ *
+ * Note: When updating the format, remember to keep
+ * these version+format bytes.
+ *
+ * // In this version, `session_format`
+ * // indicates whether
* // MBEDTLS_SSL_SERIALIZED_STRUCTURES_LOCAL_ONLY
* // is set, plus the setting of those compile-
* // time configuration options which influence
