Reference CID Draft in Connection ID documentation in config.h
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 2f46be4..262a9be 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1329,9 +1329,10 @@
/**
* \def MBEDTLS_SSL_CID
*
- * Enable support for the DTLS Connection ID extension which
- * allows to identify DTLS connections across changes in the
- * underlying transport.
+ * Enable support for the DTLS Connection ID extension
+ * (version draft-ietf-tls-dtls-connection-id-04)
+ * which allows to identify DTLS connections across changes
+ * in the underlying transport.
*
* Setting this option enables the SSL APIs `mbedtls_ssl_set_cid()`
* and `mbedtls_ssl_get_peer_cid()`. See their documentation for more