[client_ip] returns the IP address of the current client.

The [client_ip] method can be used in a conditional expression compared with a string that contains wildcards.
[If(Client_IP == '10.*.*.*')] ... [/If] will return True for any clients that are on machines in the 10.x.x.x subnet.

Returning the result of [client_ip] is equivalent to [web_request->remoteAddr]