The <cscm:when-not> tag is part of the multichannel framework that lets you build portals for mobile devices.
This tag renders its content for any client classification not listed in this tag's "client" attribute. The client name comes from the HTTP request and is mapped to a client classification in <project>\WEB-INF\client-classifications.xml.
<tagName attribute="value">
</tagName>
client
Required (String) - The name(s) of the client(s) that will not be shown the enclosed content. For more than one client name, use a comma-separated list.
<cscm:when-not client="phone">
<img src="images/pda_only_logo.gif">
</cscm:when-not>