I have Yakuake on KDE autostart. When Yakuake starts, it gives a notification message along the lines of "yakuake has been started and press F12 to get the terminal". This ends up in KDE's notification list and causes the notification icon to come up on the systray. It would be nice to have a command-line argument (eg. --quiet) for yakuake to suppress generation of this notification message so that it doesn't unnecessarily come up for people who have it in autostart.
You can configure it like any other notification (Configure notifications menu entry)
(In reply to Antonio Rojas from comment #1) Wow! That is true. Thanks a ton. I never figured I could do this from notifications configuration. Sorry for the noise.