DefaultStyleDefinitions is a global option that specifies the default stylesheet for all new notebooks.
EvaluatorNames is a global option that specifies the kernels that are currently configured to perform evaluations.
FormBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2} is an option for cells that specifies settings for FormBox objects within the cell.
FrontEndStackSize is a global option that specifies the size of the stack used to store data in the front end (Macintosh only).
IncludeFileExtension is an option for notebooks that specifies whether the suffix ".nb" is automatically appended to a notebook's name when it is first saved.
PrintAction is an option for notebooks that specifies the action taken when a Print[] command is evaluated by the kernel.
PrintingPageRange is an option for notebooks that specifies the range of pages of a notebook to be printed.
PrintingStartingPageNumber is an option for notebooks that specifies what number to assign to the first page of a notebook when printed.
RulerUnits is an option for notebooks that specifies the units in the ruler toolbar.
Update
(Built-in Mathematica Symbol) Update[symbol] tells Mathematica that hidden changes have been made which could affect values associated with a symbol. Update[] specifies that the value of any symbol could ...