Hiding portal pages (and other items) from Portal Navigation is a common requirement, but there is no obvious way to do this. There are some suggestions that using the Manage Pages portlet works, though I have not had any success with it. My personal approach requires xmlaccess, but has never let me down! Here's how I do it:
First, use xmlaccess to export the page, label, or other item(s) that you need to hide from navigation. For a brief tutorial about xmlaccess exporting, the following article may be helpful:
http://www-01.ibm.com/support/docview.wss?uid=swg21260098
Following is a snippet from a Portal 6.1.0.3 xmlaccess export that I took - it has been mangled slightly to fit on the page. The parameter in question is highlighted in red. If your export does not contain this parameter, just copy / paste from this article and it should work fine.
<content-node action="update" active="true" allportletsallowed="false" create-type="explicit" domain="rel".... >
<supported-markup markup="html" update="set"/>
<localedata locale="en">
<title>Enterprise Search for classic collections</title>
</localedata>
<parameter name="colorPalette" type="string" update="set"><![CDATA[bcbstp2Theme/bcbstp2Theme]]></parameter>
<parameter name="com.ibm.portal.Hidden" type="string" update="set"><![CDATA[true]]></parameter>
<parameter name="com.ibm.portal.IgnoreAccessControlInCaches" type="string" update="set"><![CDATA[false]]></parameter>
<parameter name="com.ibm.portal.bookmarkable" type="string" update="set"><![CDATA[No]]></parameter>
<parameter name="com.ibm.portal.friendly.name" type="string" update="set"><![CDATA[OmniFindSearch]]></parameter>
<parameter name="com.ibm.portal.remote-cache-expiry" type="string" update="set"><![CDATA[0]]></parameter>
<parameter name="com.ibm.portal.remote-cache-scope" type="string" update="set"><![CDATA[NON-SHARED]]></parameter>
If the parameter already exists, just change the value within the CDATA block to "
true" (to hide the page) or "
false" (to show the page), depending on what you need.
Once you're done, save the xmlaccess file (make sure you keep a back up of your original export!) and reimport to your server. The changes should be visible to Portal Navigation on the next reload.
Happy Portalling!