To enter RCON commands click the RCON web GUI button in your game panel, search for your server, click on it then enter your RCON password (set in the configuration files)
sv_say X - Send a message to all connected players (Appears at the top of the screen as an announcement)
sv_chat X - Send a chat message to all connected players (Appears in chat window)
do_shutdown X - Do a restart with announcements in x seconds (default: 60 seconds, min: 45 seconds, max: 600 seconds)
status - Display the status of all players and connections
wm_startPattern X - Force start a weather pattern (all connected players will be notified - see weather pattern list below)
mis_ban_steamid 64BITSTEAMID - Ban Player
mis_ban_status - Display the ban list
mis_ban_remove 64BITSTEAMID - Remove from ban list
mis_kick X 64BITSTEAMID - Kick from server
mis_whitelist_add 64BITSTEAMID - Add to whitelist
mis_whitelist_remove 64BITSTEAMID - Remove from whitelist
mis_whitelist_status X - Display the current whitelist