In links, text messages and ticker text certain strings are replaced by actual values of the player. This will help fetch and show content specific to the player.
For e.g. https://site.com/content?player=__cpuid__ will be replaced as
The supported variables are
__cpuid__ : Player ID of the player
__ipaddress__ : IP address of the player
__playername__ : Player name
__group__ : group of the player