detecting referral sites

[Mazinger]

Hello,

I saw some forums can detect that a user is coming from Google search, and so displaying an exclusive data to him.

How do they make so?

[James Birkett]

They may be using referring headers to detect ($_SERVER['HTTP_REFERER']).

Unless there is a modification on here, that's the only method I can think of.

[Mazinger]

Yea, I'm actually looking for the modification. Thanks anyway. :)