From d94739ce8dc061cbd8731d118fc5acdd9cbca804 Mon Sep 17 00:00:00 2001
From: neil <8305679+Neilpang@users.noreply.github.com>
Date: Sun, 16 Aug 2020 16:48:50 +0800
Subject: [PATCH] Updated Preferred Chain (markdown)

---
 Preferred-Chain.md | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/Preferred-Chain.md b/Preferred-Chain.md
index 3517038..5a57215 100644
--- a/Preferred-Chain.md
+++ b/Preferred-Chain.md
@@ -1 +1,34 @@
 Using `--preferred-chain` to select alternate chain.
+
+If the ACME CA provides multiple cert chain, you can use `--preferred-chain` to select one. Otherwise, it will get the default chain.
+
+1. For Letsencrpt.org Staging Server:
+
+    There are 2 chains provided:
+
+    |   Name            |  Default  |
+    |-------------------|-----------|
+    |   Fake LE Root X1 | Yes       |
+    |   Fake LE Root X2 |   No     |
+
+    You select the ca like:
+```
+acme.sh  --issue -d example.com .....     --preferred-chain  "Fake LE Root X2"
+```
+
+2. For Letsencrypt.org Production server:
+
+    There are 2 chains provided:
+
+    |   Name            |  Default  |
+    |-------------------|-----------|
+    |   DST Root CA X3 | Yes       |
+    |   ISRG Root X1 |   No     |
+
+    You select the ca like:
+```
+acme.sh  --issue -d example.com .....     --preferred-chain  "ISRG Root X1"
+```
+
+
+