http://l3tczdiiwoo63iwxty4lhs6p7eaxop5micbn7vbliydgv63x5zrrrfyd.onion/4.0.0/user-manual/filter-file.html
The dot needed to be escaped , i.e. preceded by a backslash, to take away its special meaning
as a joker, and make it just a regular dot. So far, the meaning is: Match from the start of the first
<script> tag in a the page, up to, and including, the text "document.referrer" ,
if both are present in the page (and appear in that
order).