Assuming[assum, expr] evaluates expr with assum appended to $Assumptions, so that assum is included in the default assumptions used by functions such as Refine, Simplify, and ...
AutoScroll is an option to SelectionMove and related functions that specifies whether a notebook should automatically be scrolled to display the current selection.
Bookmarks is an option for Manipulate and related functions that gives a list of bookmark settings.
BoxStyle is an option for three-dimensional graphics functions that specifies how the bounding box should be rendered.
ChartBaseStyle is an option for charting functions that specifies the base style for all chart elements.
ControllerMethod is an option for Manipulate, Graphics3D, Plot3D, and related functions that specifies the default way that controls on an external controller device should ...
DataReversed is an option for ArrayPlot and related functions that specifies whether data should be plotted in reverse order.
DefaultBoxStyle is a low-level option for three-dimensional graphics functions that specifies the default style to use in rendering the bounding box.
DefaultFaceGridsStyle is a low-level option for 3D graphics functions that specifies the default style to use in rendering face grids.
DefaultFrameTicksStyle is a low-level option for 2D graphics functions that specifies the default style to use in rendering frame ticks.