Implementors Note re: CAP alerts within Google Earth

As part of the continuing work on the display of all-hazards public warning messages via the Common Alerting Protocol (CAP) standard, I am drafting a document about using Google Earth KML with CAP messages. 

The latest draft Implementors Note document is at http://www.search.gov/CAP-KML-Note-v0-2.doc In this version, the recommendation is to approximate a CAP Circle with KML Polygon rather than KML LineString. (A Polygon is closed figure, and it supports the "InnerBoundaryIs" sub-element.) There is now a discussion about handling decimal precision, and there are a few other places where I'm asking for specific feedback.

I'd appreciate any comments you may have on the draft document. Please reply to 

Thanks,

Eliot