Cyan
(Built-in Mathematica Symbol) Cyan represents the color cyan in graphics or style specifications.
DefaultFontProperties is a global option that specifies various properties of a font family, such as its character encoding and whether it is monospaced.
DefaultNewInlineCellStyle is an option for cells that specifies the default style to use for new inline cells created in the notebook.
DefaultNotebook is a global option that specifies which notebook is used as a template for all new notebooks.
DeletionWarning is an option for InterpretationBox or TagBox objects that specifies whether a warning is issued if the box is deleted.
Del
(Built-in Mathematica Symbol) Del[x] displays as \[Del]x.
Diamond
(Built-in Mathematica Symbol) Diamond[x, y, ...] displays as x\[Diamond]y\[Diamond]....
DotEqual[x, y, ...] displays as x \[DotEqual] y \[DotEqual] ....
DoubleDownArrow[x, y, ...] displays as x\[DoubleDownArrow]y....
DoubleLongLeftArrow[x, y, ...] displays as x\[DoubleLongLeftArrow]y\[DoubleLongLeftArrow]....