Skip
(Built-in Mathematica Symbol) Skip[stream, type] skips one object of the specified type in an input stream. Skip[stream, type, n] skips n objects of the specified type.
SpellingDictionaries -> {opt_1 -> val_1, opt_2 -> val_2, ...} is a global option that specifies settings for spell checking.
StabilityMarginsStyle is an option to frequency response plots such as BodePlot, NyquistPlot, and NicholsPlot that specifies the styles in which the gain and phase margins ...
StackBegin[expr] evaluates expr, starting a fresh evaluation stack.
StackComplete[expr] evaluates expr with intermediate expressions in evaluation chains included on the stack.
StackInhibit[expr] evaluates expr without modifying the evaluation stack.
StreamColorFunctionScaling is an option for graphics functions that specifies whether arguments supplied to a stream color function should be scaled to lie between 0 and 1.
Streams
(Built-in Mathematica Symbol) Streams[] gives a list of all streams that are currently open. Streams["name"] lists only streams with the specified name.
StringTrim["string"] trims whitespace from the beginning and end of " string".StringTrim["string", patt] trims substrings matching patt from the beginning and end.
SubMinus[expr] displays as expr_-.