These are used to override or specify the security settings when security is enabled. These are the possible settings:
PHP_HANDLING - true/false. If set to true, the $php_handling setting is not checked for security.
IF_FUNCS - This is an array of the names of permitted PHP functions in IF statements.
INCLUDE_ANY - true/false. If set to true, any template can be included from the file system, regardless of the $secure_dir list.
PHP_TAGS - true/false. If set to true, {php}{/php} tags are permitted in the templates.
MODIFIER_FUNCS - This is an array of the names of permitted PHP functions used as variable modifiers.