How does Nautilus automatically create a quicklist of favorite places?

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http://askubuntu.com – Right clicking the Nautilus icon in the unity side bar brings up first a list of favorite locations, followed by the standard "Open a New Window" command. The "New Window" command is defined in /usr/share/applications/nautilus.desktop, but the list of favorites is not. How does the .desktop file know to fill the launcher with the list of favorites? Where does this information come from? Is this some "special property" of Nautilus, or can such "favorites" entries be defined by our own applications? (HowTos)