note: If you use the "advanced" editor (which is the default now) - with every letter or character you type, the editor will make a suggestion in a drop down box. If you keep typing, it will narrow the choices - or, you can just click on the one you want when you see it. You may still have to edit a bit.
The $DJUS stands for indexes developed by Dow Jones for many industries - US I think because the indexes include only companies based (mainly?) in the US.