Marking menus appear at the mouse pointer when you use certain key and mouse button combinations. They allow you to quickly select an action from a small list.
Marking menus are common in the Maya interface:
The q, w, e, and r keys have default marking menus attached to them.
To select an item from a marking menu
It doesn’t matter how far you drag or if you hit the item exactly. This allows you to make the drag very quickly with a little practice.
Dragging over an item with a submenu attached shows the submenu.