I've been looking at the themes that have been released recently, and realised that not everyone is aware of the use and also, more importantly, the restrictions for the 'SECURE' layout.
The reason it is called 'secure' is because of its usage within Moodle courses. Because of its secure nature the secure.php file can not have any links that take the user out of that page. This means no logout, no custommenu and no a.brand link, as well as no footer.
Odd you might think, but this is so that when used in a TEST the student cannot leave the page.
Checkout the simple layout of
theme/clean/layout/secure.php
Hope this helps,
Mary