The technical tag #EVAL{} returns the value calculated by evaluating the PHP expression that is passed as an argument:
#EVAL{2*7} will display 14,
#EVAL{_DIR_IMG_PACK} will display the path to the ecrire/img_pack/ directory,
#EVAL{phpversion()} will display the server’s PHP version number
#EVAL{$_SERVER['REQUEST_URI']} ...
Since this tag interprets PHP code live, it needs to be employed with caution.