feel free to keep it strictly simple...
headers.inc

Since LEPTON 3.0.2 we modified get_page_headers and footers process.

 

Addon authors and template authors, who use headers.inc and/or footers.inc in their modules or templates now can add all necessary and custom files to the head and foot of their addon.

The modified process will now check, if css-files or js-files are already loaded and prevent double loading.

This is almost important for js-files to prevent code misbehaviour on your site.

 

And at least it makes working for authors much easier for they didn't have to look for other addons.

Please have a look at the semantic template or algos theme if you want an example how to use it.