@amenadiel: -1 Wrong on both counts.

Location looks at the final internal filename after everything has been evaluated, and does not include query parameters.

Query parameters:
/index.php?q=abc is seen as /index.php by the Location-test.

Wordpress and other nice-url features:
/blog/2012/my-awesome-article would be internally rewritten to /index.php?q=/blog/2012/my-awesome-article
/index.php?q=/blog/2012/my-awesome-article is seen as /index.php by the Location-test.