Several functions were given new, optional parameters in PHP 5.3:
PHP Core:
clear_realpath_cache and
     filename.
    
   context.
    
   escape.
    
   details.
    
   is_xhtml.
    
   scanner_mode.
    
   mode.
    
   params.
    
   before_needle.
    
   json:
options.
    
   depth.
    
   new.
    
   New method parameters in PHP 5.3.0:
PHP Core:
previous.