LinebreakAdjustments is an option for selections that sets parameters used for calculating where automatic line breaks should be inserted.
LogitModelFit[{y_1, y_2, ...}, {f_1, f_2, ...}, x] constructs a binomial logistic regression model of the form 1/(1 + E -(\[Beta]_0 + \[Beta]_1 f_1 + \[Beta]_2 f_2 + \ ...)) ...
PhaseMargins[sys] gives the phase margins of a linear time-invariant system sys.
PrivateEvaluationOptions -> {opt_1 -> val_1, opt_2 -> val_2} is an option for selections that specifies settings for evaluation-related suboptions.
ProbitModelFit[{y_1, y_2, ...}, {f_1, f_2, ...}, x] constructs a binomial probit regression model of the form 1/2 (1 + erf((\[Beta]_0 + \[Beta]_1 f_1 + \[Beta]_2 f_2 + \ ...
expr //. rules repeatedly performs replacements until expr no longer changes.
SpellingOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for notebooks that specifies settings for spell checking.
SyntaxForm is an option for InterpretationBox and TagBox objects that specifies the precedence level to use when the InterpretationBox or TagBox is considered as an operator.
ValueQ
(Built-in Mathematica Symbol) ValueQ[expr] gives True if a value has been defined for expr, and gives False otherwise.
$PreRead is a global variable whose value, if set, is applied to the text or box form of every input expression before it is fed to Mathematica.