I want to show certain content if traffic comes to my wordpress site from google search. I want to use $_SERVER["HTTP_REFERER"]
. Security is not a huge issue -- if some client really wants to lie that they are coming thru google that is no big deal (they'll just see an ad). I also understand that I need to check what they send through $_SERVER["HTTP_REFERER"]
for malicious code. However, I see that according to answers in this post Determining Referer in PHP not all browsers send HTTP_REFERER.
What browsers don't send it? What versions?