From 9926dbf09d0f7e1181177fee6e8a96bde0d28a51 Mon Sep 17 00:00:00 2001
From: Hatter Jiang <jht5945@gmail.com>
Date: Thu, 22 May 2025 23:55:43 +0800
Subject: [PATCH] feat: update readme

---
 README.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/README.md b/README.md
index bd3725a..ddfc9a1 100644
--- a/README.md
+++ b/README.md
@@ -247,6 +247,9 @@ SSH to server:
 ssh -i id_user root@example.com
 ```
 
+<br>
+> `external_*` subcommands follow <<Cryptography external command specification>>
+> Specification: https://openwebstandard.org/rfc1
 
 <br><br>