Is it better to use require_once('filename.php') or require_once 'filename.php';

Question

Is this just a stylistic difference, or does using require_once('filename.php') vs require_once 'filename.php' have actual load/efficiency differences?

Answer 1

Pear Coding Standards say :

"include_once and require_once are statements, not functions. Parentheses should not surround the subject filename."

Source : http://pear.php.net/manual/en/standards.including.php