When you create a deformer, you can use
Component Tag expressions to define deformer memberships dynamically, letting you create custom groupings of components, or
deformer sets, which is the legacy method of putting deformable object points into a grouping known as a "deformer set".
Note: To work with Component Tags, ensure that the
Component Tags option in the
Animation (Settings) Preferences is turned on.
Learn more about creating and editing Component Tags or deformer sets with the tools described here: