DefaultNotebook is a global option that specifies which notebook is used as a template for all new notebooks.
DefaultDuration is an option to Animate and related functions that specifies the default total duration of the animation in seconds.
DefaultStyleDefinitions is a global option that specifies the default stylesheet for all new notebooks.
GridDefaultElement is an option for the low-level function GridBox that specifies what to insert when a new element is created interactively in a GridBox.
DefaultNaturalLanguage is an option for character selections that specifies the language used when checking the spelling of a word in a human natural language selection.
DefaultDuplicateCellStyle is a notebook option that specifies the default style to use for cells created by automatic duplication of other cells in the notebook.
CommonDefaultFormatTypes -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option that specifies default formats for newly created cells.
DefaultNewInlineCellStyle is an option for cells that specifies the default style to use for new inline cells created in the notebook.
DefaultLabelStyle is a low-level option for formatting and related constructs that specifies the default style to use in displaying their label-like elements.
DefaultTicksStyle is a low-level option for graphics functions that specifies the default style to use in rendering ticks.