REPLY

The REPLY command is used to respond to a REQUEST. The payload or message may be interpreted according to the tag. If the tag is unknown, the message may be discarded.
Sending a Reply to a Target
Usage: REPLY <target> <tag> :<message>
<target> The target of the reply (nickname or channel).
<tag> A tag indicating the format or type of the reply.
<message> The data to be sent as part of the reply.
Sending a Reply to Users in a Channel
Usage: REPLY <channel> [<nicklist>] <tag> :<message>
<channel> The target channel.
<nicklist> A comma-separated list of target users in the channel.
<tag> A tag indicating the format or type of the reply.
<message> The data to be sent as part of the reply.

(See section 6.4 of IRCX)