DefaultDuration is an option to Animate and related functions that specifies the default total duration of the animation in seconds.
DihedralGroup[n] represents the dihedral group of order 2 n.
ErrorBox[boxes] is a low-level box construct that represents boxes that cannot be interpreted in input or output.
ExportAutoReplacements is an option for cells that specifies which replacement rules Mathematica automatically applies when exporting text.
Expression is a symbol that represents an ordinary Mathematica expression in Read and related functions.
FileHash["file"] gives an integer hash code for the contents of the specified file.FileHash["file", " type"] gives an integer hash of the specified type.
FileType["file"] gives the type of a file, typically File, Directory, or None.
FrameBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for cells that specifies default settings.
GraphHighlightStyle is an option to Graph and related objects that specifies styles to use for highlighted graph elements.
GraphQ
(Built-in Mathematica Symbol) GraphQ[g] yields True if g is a valid Graph object and False otherwise.