The @ operator sets the error_reporting() value to 0.
This means you can use it with your own Error Handler too. for example:
function userErrorHandler($errno, $errmsg, $filename, $linenum, $vars) {
if (error_reporting())
echo $errmsg;
}
set_error_handler("userErrorHandler");
function test(){
trigger_error("Error Message", E_USER_WARNING);
}
@test(); // doesn't output anything