Prevent application to be shown in panel/taskbar of openbox
For programs that are running all the time, it is convenient to prevent them from being displayed in the panel.
Fortunately, openbox includes all we need to accomplish this goal in ~/.config/openbox/rc.conf, where you define the desired program in the applications section (at the end of the file).
Among many other options (which are explained in the commented section of rc.conf), you can chose skip_taskbar.
<application name="urxvt"> <skip_taskbar>yes</skip_taskbar> </application>
After restarting X, the chosen application will be excluded from the panel.
As an example application, urxvt is shown here (for further info on how to run it transparently in the background of openbox dektop, see here. This option is exceptionally nice for this purpose, since the terminal will be running all the time, so I don’t really need it to show up in the taskbar.)