"RTell" sends a message string to the remote user specified. "ics" stands for the name of the ICS server from the "rlist" list of available Servers using the IIC Communication System.
rtell knopper@gics Hi!
The server gives you some feedback that the message has been sent.
When you receive a "rtell" it will appear like this:
User@ICS tells you: <message>
If you tell something to channel 4 (the IIC Common Channel), the message will go to everyone listening to channel 4 on all IIC-connected Servers.
See also: channel, iic, rlist, rwho, rinfo