PHP 5.3.0 introduces two new error levels: E_DEPRECATED 
   and E_USER_DEPRECATED. The
   E_DEPRECATED error level is used to indicate that a
   function or feature has been deprecated. The
   E_USER_DEPRECATED level is intended for indicating
   deprecated features in user code, similarly to the
   E_USER_ERROR and E_USER_WARNING 
   levels.
  
   The following is a list of deprecated INI directives. Use of any of these INI
   directives will cause an E_DEPRECATED error to be thrown
   at startup.
  
Deprecated functions:
is_dst parameter to mktime().
     Use the new timezone handling functions instead.
    
   Deprecated features: