Set the order of non-builtin tray applications in Icewm

I have several applications in my system tray which are not the default monitoring gadgets of Icewm. For example, below you can see, from left to right, \ **pnmixer**, **nm-applet**, a keyboard leds indicator **trayleds.py**, a brightness indicator **traybr.py**, the battery level indicator and the network monitoring widget (the last two are Icewm builtins). The order of the first four, non-builtin is apparently randomly defined at startup. How may I fix the order for them (say, , , \ and )? man icewm-winoptions mentions > **order**: NUMBER (default: 0) > > The sorting order of task buttons and tray icons. The default value is zero. Increasing positive values go farther right, > while decreasing negative values > go farther left. The order option applies to the task pane, the tray pane and the system tray. but how can I find out the appropriate names to add to ~/.icewm/winoptions?