What are the template variables to identify that a page is a term or user?
I think a better way to hide the title on user and taxonomy term pages would be to use a preprocess_page function in your themes template.php. This way you are keeping your page.tpl.php cleaner and separating logic.

/**
* Implements hook_preprocess_page
*/
function MY_THEME_preprocess_page(&amp;$variables) {
    if( (arg(0)=='user' &amp;&amp; arg(2)=='') || (arg(0)=='taxonomy' &amp;&amp; arg(1)=='term' &amp;&amp; arg(3)=='') ) {
        $variables['title'] = FALSE;
    }
}


This will only hide the title on the view pages, but it will still be there when editing content. This is done by checking that arg(2) is empty on user pages and arg(3) is empty on taxonomy term pages as if editing content these would contain the string "edit".

As pointed out by clive the line in your page.tpl.php would need to read:

&lt;?php if ($title): ?&gt;
   &lt;h1 class="page-header"&gt;&lt;?php print $title; ?&gt;&lt;/h1&gt;
&lt;?php endif; ?&gt;


Once you have added this code then you will need to clear the cache to see the changes.