AutoIndent is an option for Style and Cell that specifies what automatic indentation should be done at the beginning of a new line after an explicit return character has been ...
AutoOpenPalettes is a global option that specifies the palettes that are automatically opened when Mathematica is started.
Booleans represents the domain of Booleans, as in x \[Element] Booleans.
CellFrame is an option for Cell which specifies whether a frame should be drawn around a cell.
CommonestFilter[image, r] transforms image by replacing each pixel with the most common pixel value in its range r neighborhood.CommonestFilter[data, r] applies commonest ...
CompiledFunction[args...] represents compiled code for evaluating a compiled function.
Control
(Built-in Mathematica Symbol) Control[{u, dom}] represents an interactive control for the variable u in the domain dom, with the type of control chosen to be appropriate for the domain ...
EvaluationObject[n, expr, ...] represents an expression submitted for evaluation on any available parallel kernel.
EvaluatorNames is a global option that specifies the kernels that are currently configured to perform evaluations.
ExtendedGCD[n_1, n_2, ...] gives the extended greatest common divisor of the integers n_i.