Rant on.
This and other repetitive questions really peev me off. There is a huge wealth of info in the archives on dozens of similar questions and I feel for the members that actually do the research and post the results - CLG for example and his F series diff listing - one of very many.
I don't have an answer, other than to create a sub-forum that questions are moved to un-answered, called SEARCH.
Rant off.
Mitch.