Why is there no documentation for $_SERVER[ HTTP_CLIENT_IP ] in php on official documentation php.net?
It seems like there have not have any kind documentation about $_SERVER[ HTTP_CLIENT_IP ] in the internet. Not even reference website such as tutorialpoint or w3school have information about this.
php.net: http://php.net/manual/en/reserved.variables.server.php
tutorial point: https://www.tutorialspoint.com/php/php_predefined_variables.htm
w3school: https://www.w3schools.com/php/php_superglobals.asp
Yet, there are many comments or tutorials in forums uses $_SERVER[ HTTP_CLIENT_IP ] to get a more accurate visitor's IP address. Such as:
stackoverflow questions:Will the value of a set $_SERVER['HTTP_CLIENT_IP'] be an empty string?
information stack exchange: https://security.stackexchange.com/questions/129662/best-approach-to-get-users-ip/129664#129664
Also, there are mention about this in the user contributed notes in php.net, but nothing official
So, is $_SERVER[ HTTP_CLIENT_IP ] actually a real thing as official documentation does not have information about this?
Can $_SERVER[ HTTP_CLIENT_IP ] actually get the "real" IP address of the visitor in a shared network? Thank You