Provide additional clarification for Section references

[bdaehlie]

From @jprenken: There are a few remaining section references ("Section X") that don't specify which document (the BRs, or this document) they refer to. Although this document is the default interpretation, I wonder if we should clarify these by saying "...of this document," like we already do with a few such references.

We should do this after we have shipped a combined CP/CPS.