Have you ever wanted to make a Component Family with the Category set to Walls? Or Roofs? Or some other system Category? There are no templates for this, and it doesn’t show up in the Family Category dialog box, so you may think that you limited to using In-Place families when you want the category to be Walls, Roofs or similar.
An interesting offshoot of the method that I described at this link is that when you save the In-Place family as an RFA, it adopts the Category that it had AS an In-Place Family!!
In simple terms:
Make an in-place Wall family with some geometry in it.
One easy way to determine if a family Category is Cuttable is by looking in the Object Styles dialog box. If there is a gray box in the ‘Cut’ column, that Category is not cuttable. See image below (from 2012):
I don’t know about you, but I would love an updated Families Guide for 2011.
Some of the information in this guide is invaluable. I have actually requested that Autodesk put together a comprehensive guide relating to Revit Categories (SR# 1-9298685321 – The help file does not describe the unique properties of each Category).
Here is an example of the information in the 2010 guide (this is copyright to Autodesk obviously):