A page with PHP sets $title for its wrapper in its .php. A plain .pad, or an .html page dropped into the application, says it with {meta}:

PHP
HTML
fragments/page_meta_1.pad
Result
{meta title='Monthly report', layout='_layouts/report'}

<p>{$title}: revenue 12.500</p>

Report

Monthly report: revenue 12.500

Generated by PAD

What it can say

When it is read

The tag is read while the page is assembled: after the PHP of _inits.php and of the page itself, before anything renders - so it has the last word over a $title the PHP set, and its values may use the PHP's variables. It must stand directly in the page's own template; the tag itself prints nothing. The cache time is read from the file before the cache is looked in, so there only plain values count.