Add the error code for missing user agent

ax3l · ax3l · commit 87bcf92f91e2 · 2013-11-27T13:59:49.000+01:00
- allows to google the problem
- Status 403: Forbidden
diff --git a/content/v3.md b/content/v3.md
@@ -386,6 +386,15 @@ Here's an example:
 User-Agent: Awesome-Octocat-App
 </pre>
 
+The error without an user agent looks like this:
+
+<pre class="terminal">
+Status: 403 Forbidden
+Request forbidden by administrative rules.
+Please make sure your request has a User-Agent header.
+Check https://developer.github.com for other possible causes.
+</pre>
+
 ## Conditional requests
 
 Most responses return an `ETag` header. Many responses also return a `Last-Modified` header. You can use the values
