If name is specified, this command stores name (which should be the name of the host on which the application is executing) in window 's WM_CLIENT_MACHINE property for use by the window manager or session manager. The command returns an empty string in this case. If name isn't specified, the command returns the last name set in a wm client command for window. If name is specified as an empty string, the command deletes the WM_CLIENT_MACHINE property from window.
Use this page to discuss why and how you would use it.
The wm client command is used to provide some level of compliance with the ICCCM. In order for the session manager to be able to restore an application, it must know on which host the application is running. The best way to do this is:
wm client . [info hostname]
You should also use the wm command command to set the application command, the most basic way being:
wm command . [linsert $argv 0 $argv0]