diff --git a/README.md b/README.md
index 50d2cfb..2d31c67 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,7 @@ https://github.com/Neilpang/acmetest
 
 - Webroot mode
 - Standalone mode
+- Standalone tls-alpn mode
 - Apache mode
 - Nginx mode
 - DNS mode
@@ -225,8 +226,20 @@ acme.sh --issue --standalone -d example.com -d www.example.com -d cp.example.com
 
 More examples: https://github.com/Neilpang/acme.sh/wiki/How-to-issue-a-cert
 
+# 5. Use Standalone ssl server to issue cert
 
-# 5. Use Apache mode
+**(requires you to be root/sudoer or have permission to listen on port 443 (TCP))**
+
+Port `443` (TCP) **MUST** be free to listen on, otherwise you will be prompted to free it and try again.
+
+```bash
+acme.sh --issue --alpn -d example.com -d www.example.com -d cp.example.com
+```
+
+More examples: https://github.com/Neilpang/acme.sh/wiki/How-to-issue-a-cert
+
+
+# 6. Use Apache mode
 
 **(requires you to be root/sudoer, since it is required to interact with Apache server)**
 
@@ -246,7 +259,7 @@ We don't want to mess your apache server, don't worry.**
 
 More examples: https://github.com/Neilpang/acme.sh/wiki/How-to-issue-a-cert
 
-# 6. Use Nginx mode
+# 7. Use Nginx mode
 
 **(requires you to be root/sudoer, since it is required to interact with Nginx server)**
 
@@ -270,7 +283,7 @@ We don't want to mess your nginx server, don't worry.**
 
 More examples: https://github.com/Neilpang/acme.sh/wiki/How-to-issue-a-cert
 
-# 7. Automatic DNS API integration
+# 8. Automatic DNS API integration
 
 If your DNS provider supports API access, we can use that API to automatically issue the certs.
 
@@ -348,7 +361,7 @@ If your DNS provider is not on the supported list above, you can write your own
 
 For more details: [How to use DNS API](dnsapi)
 
-# 8. Use DNS manual mode:
+# 9. Use DNS manual mode:
 
 See: https://github.com/Neilpang/acme.sh/wiki/dns-manual-mode first.
 
@@ -384,7 +397,7 @@ Ok, it's done.
 
 **Please use dns api mode instead.**
 
-# 9. Issue ECC certificates
+# 10. Issue ECC certificates
 
 `Let's Encrypt` can now issue **ECDSA** certificates.
 
@@ -416,7 +429,7 @@ Valid values are:
 
 
 
-# 10. Issue Wildcard certificates
+# 11. Issue Wildcard certificates
 
 It's simple, just give a wildcard domain as the `-d` parameter.
 
@@ -426,7 +439,7 @@ acme.sh  --issue -d example.com  -d '*.example.com'  --dns dns_cf
 
 
 
-# 11. How to renew the certs
+# 12. How to renew the certs
 
 No, you don't need to renew the certs manually. All the certs will be renewed automatically every **60** days.
 
@@ -443,7 +456,7 @@ acme.sh --renew -d example.com --force --ecc
 ```
 
 
-# 12. How to stop cert renewal
+# 13. How to stop cert renewal
 
 To stop renewal of a cert, you can execute the following to remove the cert from the renewal list:
 
@@ -456,7 +469,7 @@ The cert/key file is not removed from the disk.
 You can remove the respective directory (e.g. `~/.acme.sh/example.com`) by yourself.
 
 
-# 13. How to upgrade `acme.sh`
+# 14. How to upgrade `acme.sh`
 
 acme.sh is in constant development, so it's strongly recommended to use the latest code.
 
@@ -481,25 +494,25 @@ acme.sh --upgrade --auto-upgrade 0
 ```
 
 
-# 14. Issue a cert from an existing CSR
+# 15. Issue a cert from an existing CSR
 
 https://github.com/Neilpang/acme.sh/wiki/Issue-a-cert-from-existing-CSR
 
 
-# 15. Under the Hood
+# 16. Under the Hood
 
 Speak ACME language using shell, directly to "Let's Encrypt".
 
 TODO:
 
 
-# 16. Acknowledgments
+# 17. Acknowledgments
 
 1. Acme-tiny: https://github.com/diafygi/acme-tiny
 2. ACME protocol: https://github.com/ietf-wg-acme/acme
 
 
-# 17. License & Others
+# 18. License & Others
 
 License is GPLv3
 
@@ -508,7 +521,7 @@ Please Star and Fork me.
 [Issues](https://github.com/Neilpang/acme.sh/issues) and [pull requests](https://github.com/Neilpang/acme.sh/pulls) are welcome.
 
 
-# 18. Donate
+# 19. Donate
 Your donation makes **acme.sh** better:
 
 1. PayPal/Alipay(支付宝)/Wechat(微信): [https://donate.acme.sh/](https://donate.acme.sh/)