is an option for cells that specifies the keyboard shortcut to be associated with a style listed in the Format ▶ Style submenu.
Acceptable values include None and "1" through "9". Style definitions with menu command keys also generally include a MenuSortingValue to determine the location of the style in the Format ▶ Style submenu.
This option is typically specified in the style definition cell of a stylesheet.
Create a style definition for the cell style "MyTitle", which can be accessed by choosing Format▶Style▶MyTitle or pressing , and reformat the cell: