This Framework uses the "Smarty Template-Engine". This engine has it's own documentation, which you can download from the internet for free at http://smarty.net/docs.php.
You are permitted to expand the engine with your own functions. In this way, you can extend the syntax of the templates used You will find the engine in the directory "engine/". A guide can be found in the reference manual of the engine. Changes to the engine, are only recommended for experts.
About licenses: Before you make any changes, please note the license information.
Thomas Meyer, www.yanaframework.net