MathieuGroupM22[] represents the sporadic simple Mathieu group M_22.
MathieuGroupM23[] represents the sporadic simple Mathieu group M_23.
MinStableDistribution[\[Mu], \[Sigma], \[Xi]] represents a generalized minimum extreme value distribution with location parameter \[Mu], scale parameter \[Sigma], and shape ...
NumberString represents the characters of a number in StringExpression.
OutputStream["name", n] is an object that represents an output stream for functions such as Write.
PageFooters is an option for notebooks that specifies what should be inserted as the footer of each page of a notebook when it is printed.
PageHeaders is an option for notebooks that specifies what should be inserted as the header of each page of a notebook when it is printed.
ParentDirectory[] gives the parent of the current working directory. ParentDirectory["dir"] gives the parent of the directory dir.
PatternSequence[p_1, p_2, ...] is a pattern object which represents a sequence of arguments matching p_1, p_2, ....
PlusMinus[x] displays as \[PlusMinus]x.PlusMinus[x, y, ...] displays as x \[PlusMinus] y \[PlusMinus] ....