/usr/share/xsessions/subtle.desktop is in subtle 0.11.3224-xi-2.2.
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 | [Desktop Entry]
Encoding=UTF-8
Name=subtle
Comment=subtle tiling window manager
Exec=subtle
Type=XSession
|