As of PHP 5 new error reporting constant E_STRICT was introduced with
    value 2048. It enables run-time PHP suggestions on your code
    interoperability and forward compatibility, that will help you to keep
    latest and greatest suggested method of coding. E.g. STRICT message will
    warn you on using deprecated functions.
   
Note: 
     E_ALL does not include E_STRICT so it's not enabled by default