note 124667 added to filter.filters.sanitize

In the "FILTER_SANITIZE_URL" section where it says, "Remove all characters except letters, digits and $-_.+!*'(),{}|\\^~[]`<>#%";/?:@&=." is there a reason why there is a double backslash (\\)? Shouldn't there only be one backslash if it's saying that backslashes are allowed? ---- Server IP: 45.112.84.4 Probable Submitter: 38.142.137.34 (proxied: 174.67.255.108) ---- Manual Page -- http://php.net/manual/en/filter.filters.sanitize.php Edit -- https://master.php.net/note/edit/124667 Del: integrated -- https://master.php.net/note/delete/124667/integrated Del: useless -- https://master.php.net/note/delete/124667/useless Del: bad code -- https://master.php.net/note/delete/124667/bad+code Del: spam -- https://master.php.net/note/delete/124667/spam Del: non-english -- https://master.php.net/note/delete/124667/non-english Del: in docs -- https://master.php.net/note/delete/124667/in+docs Del: other reasons-- https://master.php.net/note/delete/124667 Reject -- https://master.php.net/note/reject/124667 Search -- https://master.php.net/manage/user-notes.php