RecordSeparators is an option for Read, Find, and related functions that specifies the list of strings to be taken as delimiters for records.
Return
(Built-in Mathematica Symbol) Return[expr] returns the value expr from a function. Return[] returns the value Null.
RootIntervals[{poly_1, poly_2, ...}] gives a list of isolating intervals for the real roots of any of the poly_i, together with a list of which polynomials actually have each ...
RotateLabel is an option for graphics and related functions that specifies whether labels on vertical frame axes should be rotated to be vertical.
Run
(Built-in Mathematica Symbol) Run[expr_1, expr_2, ...] generates the printed form of the expressions expr_i, separated by spaces, and runs it as an external operating system command.
SampledSoundList[{a_1, a_2, ...}, r] is a sound primitive that represents a sound whose amplitude has levels a_i sampled r times a second.
ScriptSizeMultipliers is an option for Style that specifies how much smaller to render each successive level of subscripts, etc.
SequenceHold is an attribute that specifies that Sequence objects appearing in the arguments of a function should not automatically be flattened out.
ShearingMatrix[\[Theta], v, n] gives the matrix corresponding to shearing by \[Theta] radians along the direction of the vector v, and normal to the vector n.
SoundVolume is an option to Sound and SoundNote and related functions that specifies the relative volume of the sound produced.