How to Insert “Must-Revalidate” for Magento Cache

This tip is helpful to stop the client from caching content.

Directions:

Open your local XML file.

This can be found in the [Magento Root]/app/etc/local.xml

Locate the follow area under the <global> node, and insert the code from line 26:

<![CDATA[Mon, 27 Sep 2010 12:23:53 +0000]]>

<![CDATA[demo]]>

false

<![CDATA[localhost]]>
<![CDATA[magento_user]]> <![CDATA[magento]]>
1

<![CDATA[files]]>
<!-- Add the code below this line-->
<![CDATA[nocache]]><!-- see http://php.net/manual/en/function.session-cache-limiter.php#82174 for possible values -->
<!-- Add the code above this line-->

Log into your Magento Dashbaord, and go to Systems > Cache Management

Next, select all the the Cache Types. Set your Action to: Refresh, and click the orange Submit button

We advise not to run this action for more than a week to maintain positive performance.