Revit 2011 Categories that Do NOT Have Types

I've taken the liberty of listing each Revit 2011 category that does not contain types for anyone looking to impress their spouse with some pointless trivia (more for my own future reference than anything else).

Can anyone name the one category that only has types and no instances??....


AREAS
AREA LOADS
DUCT SYSTEMS
ELECTRICAL CIRCUITS
EXTERIOR
GBXML SURFACE
LEVELS
HVAC ZONES
INTERIOR
INTERNAL AREA LOADS
INTERNAL LINE LOADS
INTERNAL POINT LOADS
LINE LOADS
MASS EXTERIOR WALL
MASS FLOOR
MASS GLAZING
MASS INTERIOR WALL
MASS OPENING
MASS ROOF
MASS SKYLIGHT
MASS ZONE
MATERIALS
OPENING
PADS
PIPING SYSTEMS
POINT LOADS
PROJECT INFORMATION
ROADS
ROOMS
SHADE
SHAFT OPENINGS
SHEETS
SPACES
SWITCH SYSTEM
UNDERGROUND
VIEWS

FACIAS is the category that only contains types and no instances...