The button sets menu gives you options for managing and customizing shortcut buttons for applying modifiers.
To display the current button set on the Modify panel:
(Configure Modifier Sets), and then choose Show Buttons to turn on this item.
This item is a toggle. Choosing Show Buttons a second time turns off the button display, and so on.
To configure a new modifier set:
(Configure Modifier Sets), and then choose Configure Modifier Sets.
To change from one button set to another:
(Configure Modifier Sets), and then choose the modifier set name from the lower part of the menu.

Displays the Configure Modifier Sets dialog to let you create a new, customized button set.