anchor.diff:    # https://www.gov.uk/foo/ -> https://www.gov.uk/foo
     # vcl_error completes the redirect
     # Don't redirect "/" to "".
  -
     if (req.url ~ "(.+)/$") {
       set req.http.x-Redir-Url = regsub(req.url, "^(.+)/$", "\1");
       error 667 req.http.x-Redir-Url;
  
positive.code: 
    # remove cookies
    if (req.backend != licensify) {
      unset req.http.cookie;
    }
    # purge individual URLs from the cache
    if(req.request == "PURGE") {
      if(!client.ip ~ purge_acl) {
        error 405 "Not allowed";
      } else {
  <% if scope.lookupvar('varnish::varnish_version') == 3 %>
  
negative.code:   unset beresp.http.X-Rack-Cache;
    unset beresp.http.X-Runtime;
  
    # Rewrite any absolute redirects to be correct
    if (beresp.http.Location) {
    <% if @govuk_platform == "production" %>
      set beresp.http.Location = regsub(beresp.http.Location, "^(\w+://[^.]+\.[^.]+\.alphagov\.co\.uk)", "https://www.gov.uk");
  