Where are HTTP_SERVER_VARS?

Can anyone point me to a location in the source where I can find out definitively what $HTTP_*_VARS are available and what are not. With track_vars on I can see: HTTP_GET_VARS HTTP_POST_VARS HTTP_COOKIE_VARS HTTP_ENV_VARS HTTP_SERVER_VARS shows only two elements (PHP_SELF and PATH_TRANSLATED) however if I turn on register_globals then I can see all the elements of HTTP_SERVER_VARS in the global scope....but what happened to those elements being in HTTP_SERVER_VARS with register_globals off and track_vars on? I had heard at one time there was supposed to be HTTP_STATE_VARS and/or HTTP_SESSION_VARS -Dave