In Ubuntu Mate 21.10 Beta there's a new category in the Compact Menu called "collection". It appears to be made up of those items that I've placed on the panel.
It's completely redundant since, um, all those items are on the panel. How can I get rid of this menu entry? It does not appear in the menu editor.
Welcome to Ubuntu MATE community!
The Collection is a new feature of MATE 1.26 which is shipped in Ubuntu MATE 21.10.
Requests to make it configurable were already filed as https://github.com/mate-desktop/mate-menus/issues/101 and Bug #1941942 “New Collection menu should be configurable” : Bugs : mate-menus package : Ubuntu .
Temporarily way to remove Collection menu category is to run the following long command (copy and paste whole code to the terminal in one shot):
mkdir -p /home/$USER/.local/share/desktop-directories/
cat <<EOF > /home/$USER/.local/share/desktop-directories/mate-collection.directory
[Desktop Entry]
Name=Collection
Comment=The most frequently used shortcuts
Icon=starred
Type=Directory
NoDisplay=true
EOF
and then reboot.
Awesome! Thanks for this great information.