ColumnSpacings is an option for the low-level function GridBox which specifies the spaces in ems that should be inserted between adjacent columns.
CommonDefaultFormatTypes -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option that specifies default formats for newly created cells.
DefaultFormatType is an option for cells that specifies the format used for displaying expressions in a newly created cell.
DefaultInlineFormatType is an option for cells that specifies the format used for displaying expressions in a newly created inline cell.
DiacriticalPositioning is an option for UnderscriptBox and related boxes that specifies how close diacritical characters are drawn to the base character.
InString[n] is a global object that is assigned to be the text of the n\[Null]^th input line.
Language is a global option that specifies the language in which menus, dialog boxes, error messages, and help files are displayed.
MultilaunchWarning is a global option that specifies whether a warning is given when you try to modify user preferences while running two copies of Mathematica simultaneously.
PodStates is an option for WolframAlpha that determines information about the states of the pods.
RowLines is an option for the low-level function GridBox that specifies whether lines should be drawn between adjacent rows.