How We Can Know The Server_referer In Php.

[contactskn 2]

Dear friends I know the basic command for finding the referer to any site. I am using that command successfully and you can see the result in the following url:

http://forums.xisto.com/no_longer_exists/

In this page you can clearly see the details of IP address and the referrer URL but with some visitors I am not able to get the referrer like visitor from Japan etc. I don't know why please if you people know the reason then is there any solution for the same if so what is it.
Thanks in advance.

[shadowx 0]

Perhaps there is no referrer.... If i had a page https://www.salesforce.com/products/platform/overview/ that found the referrer of the person visiting the page, and i just typed in the address in my browser i would have no referrer, as i didnt click a link to get there, i just typed it in. I came from "nowhere". But if i were to search google and then clicked the link my referrer would show as google.The same way that if you get a "hotlink not allowed!" message while clicking on a google image just copy the URL to the image and paste it into your browser, then you have no referrer so it lets you see the image :)It could also be that they have blocked the referrer part of the HTTP headers, you can do this with a proxy, probably a certain firewall config and with browser addons.Why is it such a big deal?