"Tell" transmits your message to the user specified. The server gives you some feedback that the message has been sent. You will also be told whether the user is playing a game currently, or is not even logged on at the moment. "t" is an alias for "tell".
As a shortcut, you can use "." as an alias for "tell user" when you want to send another message to the last person you told. That way you can keep conversations going easily.
When you receive a "tell" it will appear like this:
<User> tells you: <message>
The 'user' can also be a channel number in order to send a message to a group
of users having that channel activated. In this case, you as sender will see
the following display after sending your message:
(# --> (##)) where
# is the channel number and
## is the number of people on that
channel that received your message.
NOTE: If you tell something to channel 4, you will only get the number of people listening to the iic-channel on your own server as a feedback.
As a shortcut, you can use "," as an alias for "tell #" and your message will be sent to the last channel you gave in a "tell" command. (Compare to "xtell" command.)
See also: alias, channel, intro 2, message, say, variables, xtell