Edit Mesh > Crease
Sets > Create Crease Set
Creates a set containing the currently selected creased components (polygonal edges and vertices) when using the Crease Tool. Crease sets let you easily select those components when you need to modify them later on.
The Create
Crease Set window lets you enter a unique name for your
crease set. Crease sets can easily be selected by pressing 
+ 
+ 
to display
the list of sets via a marking menu. A selection list of the current
crease sets also appears below the Create Crease Set menu
item.
You can manage crease sets using the Outliner or the Relationship Editor. All crease sets appear in the Outliner nested within a default crease set that gets created the first time a Crease Set is created.