DefaultButton[] represents an OK button that closes a dialog, and is the default when DynamicBox[ToBoxes[If[$OperatingSystem === "MacOSX", "Return", "Enter"], StandardForm], ...
DialogInput[expr] interactively puts up expr as a dialog notebook, waits until a DialogReturn[e] is evaluated from within it, and then returns the result e. DialogInput[{x = ...
DynamicSetting[e] represents an object which displays as e, but is interpreted as the dynamically updated current value of Setting[e] if supplied as Mathematica ...
Enabled
(Built-in Mathematica Symbol) Enabled is an option for objects such as Slider that specifies whether the objects should be enabled for interactive manipulation.
FrontEndToken["cmd"] is an object which represents a front end command token, typically corresponding to a front end menu item, to be executed by FrontEndExecute. ...
Glaisher is Glaisher's constant with numerical value \[TildeEqual] 1.28243.
GraphHighlight is an option to Graph and related objects that specifies graph elements to highlight.
LindleyDistribution[\[Delta]] represents a Lindley distribution with shape parameter \[Delta].
NextPrime[n] gives the next prime above n.NextPrime[n, k] gives the k\[Null]^th prime above n.
NotebookRead[notebook] gives the expression corresponding to the current selection in the specified notebook object.