TargetFunctions is an option for functions such as ComplexExpand that specifies what functions to attempt to generate in the output.
TokenWords is an option for Read and related functions which gives a list of token words to be used to delimit words.
ToNumberField[a, \[Theta]] expresses the algebraic number a in the number field generated by \[Theta]. ToNumberField[{a_1, a_2, ...}, \[Theta]] expresses the a_i in the field ...
TraceDepth is an option for Trace and related functions which specifies the maximum nesting of evaluation chains that are to be included.
UnderoverscriptBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for selections that specifies settings for UnderoverscriptBox objects.
VertexNormals is an option for graphics primitives which specifies the normal directions to assign to 3D vertices.
WhitespaceCharacter represents a single whitespace character in StringExpression.
WindowFloating is a notebook option that specifies whether the window for the notebook should float on top of other windows when it is displayed on the screen.
WindowStatusArea is a notebook option that specifies what should appear in the status area in the frame of the window used to display the notebook.
Word
(Built-in Mathematica Symbol) Word represents a word in Read, Find, and related functions.