diff --git a/doc/advanced/config-cheat-sheet.en-us.md b/doc/advanced/config-cheat-sheet.en-us.md
index a1526cf4..6fe98f80 100644
--- a/doc/advanced/config-cheat-sheet.en-us.md
+++ b/doc/advanced/config-cheat-sheet.en-us.md
@@ -62,6 +62,9 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
    HTTP protocol.
 - `USE_COMPAT_SSH_URI`: **false**: Force ssh:// clone url instead of scp-style uri when
    default SSH port is used.
+- `ACCESS_CONTROL_ALLOW_ORIGIN`: **\<empty\>**: Value for Access-Control-Allow-Origin header,
+   default is not to present. **WARNING**: This maybe harmful to you website if you do not
+   give it a right value.
 
 ### Repository - Pull Request (`repository.pull-request`)
 - `WORK_IN_PROGRESS_PREFIXES`: **WIP:,\[WIP\]**: List of prefixes used in Pull Request