Release 2011: The Families Guide was not updated for Revit 2011. Please use the 2010 edition of the Families Guide.

Autodesk – Autodesk Revit Architecture Services & Support – Families Guide

Do you get the feeling that perhaps, if Autodesk put it off long enough, they won’t have to update some of this documentation?

With the official Wiki now in operation, and a plethora of blogs, where will Autodesk draw the line with regards to Help documentation?

You want to know which families are cuttable and which are not.  Revit 2011 help gives the answer:

Cuttable families (link):
Casework
Ceilings
Columns
Curtain Wall Panels
Doors
Floors
Generic Models
Roofs
Site
Structural Columns
Structural Foundations
Structural Framing
Topography
Walls
Windows

Non-cuttable families (link):
Balusters
Detail Items
Electrical Equipment
Electrical Fixtures
Entourage
Furniture
Furniture Systems
Lighting Fixtures
Mechanical Equipment
Parking
Planting
Plumbing Fixtures
Specialty Equipment

What is a cuttable family?

If a family is cuttable, the family displays as cut when the cut plane of a view intersects that family in all types of views.  From Revit 2011 help.