AdiIRC

Added in 1.7

/clearall [-agmnqstu]

Clears the buffer and Channelbar/Sidebar unread color of the specified window type, if no type is specified, all windows on current connection is cleared.

Switches

-a - All windows on all connections.
-g - TODO
-m - TODO
-n - Channel windows.
-p - Docking panels.
-q - Query windows.
-s - Status windows.
-t - Dcc chat windows.
-u - Custom windows.

Example

;Clear all channel and query windows
/clearall -nq

;Clear all windows on current connection.
/clearall