Admittedly the RPO sheet on site is probably due for a re-load. We haven't updated it in awhile, and it can be terse and hard to understand in obscure instances, even when it is accurate.
However, a better summary can be found at:http://www.camaros.org/options.shtml#SeatBeltOptions
If not sure where to look on site, try the Google site search on the home page - it digs out stuff pretty well. The first two hits on "seat belt" were the two above, but the summary was listed first, and might have saved you some time.