Tray icons should set the following hints to help the system tray provide a nice user interface. The name and icon hints are used if the system tray needs to refer to a tray icon; for example, the system tray may present a list of tray icons and let the user reorder them or change their properties.
_NET_WM_NAME, UTF8_STRING
This hint should be set as it would be for a normal toplevel window, as defined in the Extended Window Manager Hints Specification (EWMH). The hint MUST be in UTF-8 encoding. It provides a human-readable, localized name for the tray icon.
WM_CLASS, STRING
This hint should be set as it would be for a normal toplevel window, as defined in the ICCCM. The system tray can use it to distinguish different kinds of tray icon. This is useful for example if the system tray wants to save and restore the positions of the icons in the tray.