There are several miscellaneous functions worth mentioning here as follows:Back-Tab
This is not a key. Back-tab is accesed by holding down Shift whilst pressing the Tab
key. It reverses the direction of normal tabbing. See also Tab key.
This is not a key. Mouse click here refers to the mouse button (usually the left button
on a standard 2 button mouse).
Toggling (pressing on and off) the num lock or caps lock key makes ring as a green
light on your keyboard that switches on and off when you press the num lock or caps