Added in 3.3
/ialfill [-f] [#channel]
Performs a /who request on the specified channel. if no channel is specified, performs the request on the current active channel.
If the server supports WHOX, an extended /WHO #channel %acdfhlnrstu,T is sent to receive the account name, where T is a number that uniquely identifies the WHO request and is set to 995.
-f - Forces a ialfill even if the ial is fully populated.
#channel - The channel name to populate.