WHISPER

The WHISPER command is used to send a private message to a list of users within a channel.

Channel Whisper
Usage: WHISPER <channel> <nicklist> :<message>
<channel> The channel in which to send the whisper.
<nicklist> A list of nicknames, separated by commas, to send the message to.
<message> The message to send.

This command sends a private message to the specified users within a channel. Other users in the channel will not see the message. The nicklist is a comma-separated list of nicknames.

(See section 5.13 of IRCX)