From 0f432994b8371f4ccc58679a38d4f1decb2ed4c1 Mon Sep 17 00:00:00 2001
From: Trotyl Yu <trotyl@qq.com>
Date: Sun, 24 Sep 2017 10:15:46 +0800
Subject: [PATCH] docs(aio): document the special treatment of undefined

---
 aio/content/guide/template-syntax.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aio/content/guide/template-syntax.md b/aio/content/guide/template-syntax.md
index 4c6c481241..9c5f58c1d1 100644
--- a/aio/content/guide/template-syntax.md
+++ b/aio/content/guide/template-syntax.md
@@ -142,7 +142,7 @@ The `hero` in `{{hero.name}}`
 refers to the template input variable, not the component's property.
 
 Template expressions cannot refer to anything in
-the global namespace. They can't refer to `window` or `document`. They
+the global namespace (except `undefined`). They can't refer to `window` or `document`. They
 can't call `console.log` or `Math.max`. They are restricted to referencing
 members of the expression context.