KeyScope: "global" | "widget" | "chart" | "rail" | "overlay" | string & {}

Where a binding applies. global always; widget while the pointer or the focus is inside the widget; chart while either is on the chart itself; rail while the focus is in the tool rail; overlay while a dialog or a menu is open, when nothing else fires. The shell decides which are active (see setScopes); they are tried narrowest first.