I'm developing a CakePHP site for which I've just enabled VAS authentication using a .htaccess file:

```
AuthType VAS

AuthVasUseBasic On
AuthVasRemoteUserMap local

Require valid-user

```

I'd expect to be able to find out who was logged in by using `$_SERVER['REMOTE_USER']`, but I'm finding that the key is missing from the `$_SERVER` structure: all that's there is `$_SERVER['REDIRECT_REMOTE_USER']`. In fact, the whole structure is full of keys with the `REDIRECT_` prefix:

```
echo var_dump($_SERVER);
array(52) {
["REDIRECT_REDIRECT_REDIRECT_SCRIPT_URL"]=>  string(37) "/cake_1_2/feedbacks/edit/6" 
["REDIRECT_REDIRECT_REDIRECT_SCRIPT_URI"]=>  string(55) "http://test/cake_1_2/feedbacks/edit/6"
["REDIRECT_REDIRECT_REDIRECT_STATUS"]=>  string(3) "200" 
["REDIRECT_REDIRECT_SCRIPT_URL"]=>  string(37) "/cake_1_2/feedbacks/edit/6" 
["REDIRECT_REDIRECT_SCRIPT_URI"]=>  string(55) "http://test/cake_1_2/feedbacks/edit/6" 
["REDIRECT_REDIRECT_STATUS"]=>  string(3) "200" 
["REDIRECT_SCRIPT_URL"]=>  string(37) "/cake_1_2/feedbacks/edit/6" 
["REDIRECT_SCRIPT_URI"]=>  string(55) "http://test/cake_1_2/feedbacks/edit/6" 
["REDIRECT_HANDLER"]=>  string(8) "php5-cgi"
["REDIRECT_STATUS"]=>  string(3) "200" 
["SCRIPT_URL"]=>  string(37) ...
["REDIRECT_REMOTE_USER"]=>  string(9) "andygeers"
... 
}

```

I'm not exactly sure what's going on! This is generated first thing in a POST request, and it's not doing a redirect on this particular request.

Is this related to CakePHP, or just a general PHP issue? Any ideas what's going on? I've found quite a few pages on the internet now which suggest REDIRECT\_REMOTE\_USER is normal/common as a place to find this value, but nobody seems to know why!