With the help open,
activate "Take Command Help v.16.03" tray
causes the help to be hidden and a **TCC** icon to appear in the tray. Clicking that icon causes TCC to get focus (if it doesn't already have it), causes the tray icon to disappear, and leaves the help hidden.
WAD -- the app has to support being minimized to the tray. And Notepad doesn't.
Please explain how that works and name an app, other than a JPSoft product, which supports it?

I figure TCC is putting the icon in the tray and I wouldn't expect another app to be monitoring messages from it.