GeoIP Question - Speed & efficiency

[Chris Savery]

>All nginx variables are evaluated on demand only, therefore geo variables
>are looked up only if they are really used in a request.

Ok. Excellent, so if I only include the fastcgi param line for one location, say for index.php then it would only evaluate under that condition to pass thru to php, like this:

fastcgi_param  COUNTRY      $geo;

Which is easy then...

Thank very much,
Chris :)