note 36514 added to pcre.pattern.modifiers

Actually, the i option has no relevance to that. Your sample code gives the same results whether you have the i there or not. It's really the difference between matching with no regex, or with a regex that can match anywhere. The null regex vs the empty regex. Though if you want a regex that never matches, /(?!)/ is nicer. ---- Manual Page -- http://www.php.net/manual/en/pcre.pattern.modifiers.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+36514 Delete -- http://master.php.net/manage/user-notes.php?action=delete+36514&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+36514&report=yes Search -- http://master.php.net/manage/user-notes.php