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.
DefaultGridLinesStyle is a low-level option for 2D graphics functions that specifies the default style to use in rendering grid lines.
DefaultTicksStyle is a low-level option for graphics functions that specifies the default style to use in rendering ticks.
ExponentStep is an option for NumberForm and related functions that determines in what steps exponents are taken to increase when scientific notation is used.
GapPenalty is an option for SequenceAlignment and related functions that gives the additional cost associated with each gap corresponding to a run of insertions or deletions.
GenerateConditions is an option for Integrate, Sum, and similar functions that specifies whether explicit conditions on parameters should be generated in the result.
Inner
(Built-in Mathematica Symbol) Inner[f, list_1, list_2, g] is a generalization of Dot in which f plays the role of multiplication and g of addition.
InputStream["name", n] is an object that represents an input stream for functions such as Read and Find.