/usr/share/desktop-directories/Network.directory is in gnome-menus 3.4.0-0ubuntu1.
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]
Name=Internet
Comment=Programs for Internet access such as web and email
Icon=applications-internet
Type=Directory
X-Ubuntu-Gettext-Domain=gnome-menus-3.0
|