added a warning note that caching only works when generating display via a view file.
diff --git a/user_guide/general/caching.html b/user_guide/general/caching.html
index 6c7d35f..db3725b 100644
--- a/user_guide/general/caching.html
+++ b/user_guide/general/caching.html
@@ -89,6 +89,7 @@
<p>The above tag can go anywhere within a function. It is not affected by the order that it appears, so place it wherever it seems
most logical to you. Once the tag is in place, your pages will begin being cached.</p>
+<p class="important"><strong>Warning:</strong> Because of the way CodeIgniter stores content for output, caching will only work if you are generating display for your controller with a <a href="./views.html">view</a>.</p>
<p class="important"><strong>Note:</strong> Before the cache files can be written you must set the file permissions on your
<dfn>system/cache</dfn> folder such that it is writable (666 is usually appropriate).</p>