PrincipalValue is an option for Integrate that specifies whether the Cauchy principal value should be found for a definite integral.
QuadraticIrrationalQ[x] gives True if x is a quadratic irrational and False otherwise.
ReadProtected is an attribute that prevents values associated with a symbol from being seen.
p ... or RepeatedNull[p] is a pattern object that represents a sequence of zero or more expressions, each matching p.
RotateLabel is an option for graphics and related functions that specifies whether labels on vertical frame axes should be rotated to be vertical.
SaveDefinitions is an option to Manipulate and related functions that specifies whether current definitions relevant for the evaluation of the expression being manipulated ...
SequenceHold is an attribute that specifies that Sequence objects appearing in the arguments of a function should not automatically be flattened out.
SetSystemOptions["name" -> value] resets the value for the internal system option with the specified name.
ShowShortBoxForm is an option for cells that specifies whether box expressions, which are used to represent two-dimensional forms in a cell, are displayed in a more compact ...
SpellingDictionaries -> {opt_1 -> val_1, opt_2 -> val_2, ...} is a global option that specifies settings for spell checking.