ColorDataFunction[range, ...] is a function that represents a color scheme.
ControlActive[act, norm] evaluates to act if a control that affects act is actively being used, and to norm otherwise.
CovarianceEstimatorFunction is an option for generalized linear model fitting functions that specifies the estimator for the parameter covariance matrix.
DamerauLevenshteinDistance[u, v] gives the Damerau\[Dash]Levenshtein distance between strings or vectors u and v.
DiscreteDelta[n_1, n_2, ...] gives the discrete delta function \[Delta] (n_1, n_2, ...), equal to 1 if all the n_i are zero, and 0 otherwise.
DispersionEstimatorFunction is an option for generalized linear model fitting functions that specifies the estimator for the dispersion parameter.
Divisible[n, m] yields True if n is divisible by m, and yields False if it is not.
Epilog
(Built-in Mathematica Symbol) Epilog is an option for graphics functions that gives a list of graphics primitives to be rendered after the main part of the graphics is rendered.
ExtentSize is an option to DiscretePlot and DiscretePlot3D that specifies how far to extend out from each plot point.
FaceGrids is an option for three-dimensional graphics functions that specifies grid lines to draw on the faces of the bounding box.