Synopsis:
   on [<modes>]topic [<serial#>] [-|^]<match> { <action> }

Description:
   This hook is triggered when the topic is changed on any channel the
   client is on.

Parameters:
   $0    nickname of person changing topic
   $1    channel topic was changed on
   $2-   new topic

See Also:
   on(5) 331, 332; topic(1)