MathieuGroupM24[] represents the sporadic simple Mathieu group M_24.
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.
PrintTemporary[expr] prints expr as a temporary cell in a notebook, removing it when the evaluation of the current input line is complete.
ScheduledTaskObject[id, expr, spec, ...] is a task object specifying future evaluation of expr according to spec.
SpellingDictionaries -> {opt_1 -> val_1, opt_2 -> val_2, ...} is a global option that specifies settings for spell checking.
StreamStyle is an option to StreamPlot, StreamDensityPlot, and related functions that determines the style to use for drawing streamlines.
Subsuperscript[x, y, z] is an object that formats as x_y^z.
Superscript[x, y] is an object that formats as x^y.
Underoverscript[x, y, z] is an object that formats as x_y^z.
$HistoryLength specifies the number of previous lines of input and output to keep in a Mathematica session.