Built-in Mathematica Symbol

StyleBox

StyleBox[boxes, options]
is a low-level representation of boxes to be shown with the specified option settings.

StyleBox[boxes, "style"]
uses the option setting for the specified style in the current notebook.

StyleBox is the low-level representation of Style. Except for low-level notebook expression manipulation, StyleBox should not need to be used directly.

AutoSpacing	True	whether to adjust character spacings automatically
LineIndent	1.0	distance in ems to indent for each nesting level
LineIndentMaxFraction	0.5	maximum fraction of line width to indent
ScriptMinSize	4	the minimum point size to use for subscripts, etc.
ScriptSizeMultipliers	0.71	how much smaller to make each level of subscripts, etc.
ShowContents	True	whether to make boxes visible or just leave space for them
SpanLineThickness	Automatic	thickness in printer's points of fraction lines, etc.
SpanMaxSize	Automatic	maximum size of expandable characters in units of font size
SpanMinSize	Automatic	minimum size of expandable characters in units of font size
SpanSymmetric	True	whether vertically expandable characters should be symmetric about the axis of the box they are in

In StandardForm and InputForm input, StyleBox is by default ignored, so that StyleBox[box, spec] is interpreted just as box would be.

When StyleBox objects are nested, the options of the innermost one control the display of particular boxes.

In StandardForm, explicit StyleBox objects are output literally. You can use DisplayForm to see the display form of such objects.

Style boxes or text according to a style option:

Out[1]//DisplayForm=

Out[2]//DisplayForm=

Use a named style:

Out[1]//DisplayForm=

Out[2]//DisplayForm=

Display some text that cannot be selected except as a whole:

Out[1]//DisplayForm=

Out[2]//DisplayForm=

By default, spanning characters such as braces do not grow arbitrarily large:

Out[1]//DisplayForm=

Use SpanMaxSize to allow braces to grow to the full size:

Out[2]//DisplayForm=