Input from Above copies and pastes contents of the nearest preceding input cell.
X Environment Information opens a dialog box that displays the current attributes of the X front end environment (X only).
ActiveStyle is an option for Hyperlink and related constructs that specifies styles to add when the constructs are active, typically as a result of the mouse being over them.
AlphaChannel[image] returns the alpha channel of image.
Beep
(Built-in Mathematica Symbol) Beep[] generates an audible beep when evaluated.
CellDynamicExpression is an option for cells that specifies an expression to be dynamically updated whenever the cell is visible on-screen.
CellEpilog is an option for Cell which gives an expression to evaluate after each ordinary evaluation of the contents of the cell.
ClearSystemCache[] clears internal system caches of stored results.
DefaultFaceGridsStyle is a low-level option for 3D graphics functions that specifies the default style to use in rendering face grids.
DefaultFieldHintStyle is a low-level option for InputField that specifies the default style to use for displaying the field hint.