SectorOrigin is an option to PieChart and related functions that specifies where sectors should start.
SectorSpacing is an option to PieChart and related functions that specifies radial spacing of sectors.
SelfLoopStyle is an option for GraphPlot and related functions that specifies how to draw self-loops that connect a vertex to itself.
lhs := rhs assigns rhs to be the delayed value of lhs. rhs is maintained in an unevaluated form. When lhs appears, it is replaced by rhs, evaluated afresh each time.
SoundNote[pitch] represents a music-like sound note with the specified pitch.SoundNote[pitch, t] takes the note to have duration t.SoundNote[pitch, {t_min, t_max}] takes the ...
SphericalHankelH1[n, z] gives the spherical Hankel function of the first kind h_n^(1)(z).
SpheroidalJoiningFactor[n, m, \[Gamma]] gives the spheroidal joining factor with degree n and order m.
Splice
(Built-in Mathematica Symbol) Splice["file"] splices Mathematica output into an external file. It takes text enclosed between < * and * > in the file, evaluates the text as Mathematica input, and replaces ...
StringReverse["string"] reverses the order of the characters in " string".
StyleDefinitions is an option for notebooks that gives definitions for the styles that can be used in a notebook.