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.
Masking
(Built-in Mathematica Symbol) Masking is an option for various image analysis and processing functions that specifies on which regions they should operate.
MaxPlotPoints is an option for plotting functions like ArrayPlot and ListPlot3D that specifies the maximum number of points that will explicitly be included in the output.
NullRecords is an option for Read and related functions which specifies whether null records should be taken to exist between repeated record separators.