I found another documentation error in the "Getting Started with Rails Guide." The comment.rb model file needs to have the following line of code added, in order to work correctly:
attr_accessible :name, :tag_attributes
You can make these changes yourself.
http://weblog.rubyonrails.org/2012/3/7/what-is-docrails/
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Ray
I don't see where tag_attributes are currently referenced in the guides. What am I missing?