/usr/share/xsessions/jwm.desktop is in jwm 2.3.7-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | [Desktop Entry]
Name=Jwm
Comment=Minimalistic pure X11 window manager with menu/tray support
Type=Application
Terminal=False
Exec=/usr/bin/jwm
TryExec=jwm
Keywords=X11;floating;windowmanager;
[Window Manager]
SessionManaged=true
|