ImageMargins is an option that specifies the absolute margins to leave around the image displayed for an object.
InterpretationBox[boxes, expr] is a low-level box construct that displays as boxes but is interpreted on input as expr.
Locator
(Built-in Mathematica Symbol) Locator[{x, y}] represents a locator object at position {x, y} in a graphic. Locator[Dynamic[pos]] takes the position to be the dynamically updated current value of pos, with ...
MaxStepSize is an option to functions like NDSolve that specifies the maximum size of a single step used in generating a result.
MultiedgeStyle is an option for GraphPlot and related functions that specifies how to draw multiple edges.
NumberSeparator is an option for NumberForm and related functions which gives the string to insert at breaks between digits.
OpenAppend["file"] opens a file to append output to it, and returns an OutputStream object.
PlotRangePadding is an option for graphics functions that specifies how much further axes etc. should extend beyond the range of coordinates specified by PlotRange.
SectorOrigin is an option to PieChart and related functions that specifies where sectors should start.
SelfLoopStyle is an option for GraphPlot and related functions that specifies how to draw self-loops that connect a vertex to itself.