Differences between Guidelines and Implementing documents

Hi! The Implementing document is almost, but not quite, a superset of the Guidelines document, but not exactly. Are these differences intentional? It seems to me that it would be best of the Implementing document could function as a superset of the basic document. This way a reader could rely pretty much on the Implementing document rather than having to refer to both, and we wouldn't t have to worry about people missing the small amount that's only in the basic document.

The primary difference is that most of the main document's Introduction is not repeated in the Implementing document. Is there a strong reason for this?

The other, more minor differences are that (a) the copyright date is 2009 in and 2010 in the other (both should probably include 2011), and (b) that the sentence "The group does not expect this document to become a W3C Recommendation" is only buried in the Patents paragraph in the Implementing document.

     Thanks,
     Greg