http://www.perlmonks.org?node_id=346688


in reply to Re: Unexpected qr// behavior
in thread Unexpected qr// behavior

To make things even more clear (I hope), I'll just add that you can pass modifiers to qr, just like you can for normal regexes, like this:
$re = qr/<!--.*?-->/s; print $re;
which prints
(?s-xim:<!--.*?-->)
That is: /s enabled, and /x, /i and /m disabled.