_Added in 1.9.0_

*<notextile>on <level>:OPEN:<?|=|*>:<matchtext>:<commands></notextile>*
*<notextile>on <level>:OPEN:<=|*>:<commands></notextile>*

Trigger for various events relating to the opening of a window of different types of windows.

Note: If you halt an [[on OPEN]] event triggered by an incoming private message, no [[on TEXT]]/[[on ACTION]] events is triggered

For private chat windows, [[on OPEN]] only triggers when opening a new private window from a incoming private message.

For private chat windows, the <matchtext> parameter is required.

For DCC chat windows, the <matchtext> parameter is excluded, and it triggers only on successful connection.

_See also [[on CLOSE]]._

_Haltable using ^_

*Parameters*

&lt;level&gt; - The [[User Access Level]] for the event to trigger.
&lt;?|@|=|!|*&gt; - The [[Matchtarget]] to listen to.
&lt;matchtext&gt; - The [[Matchtext]] to listen to.
&lt;commands&lt; - The commands to be performed when the event listener's criteria is met.

*Example*

<pre>
; Print a message when a query window is opened.
on *:OPEN:?:*:echo -ag Opened query window for $nick

; Print a message when a dcc chat window is established.
on *:OPEN:=:echo -ag Opened dcc chat window for $nick
</pre>