Originally Posted by
jimbo99
Also bear in mind that many posters are US based - where often First is applied to domestic flights whereas in Europe it would be "Business" (or "Club").
This is true. But some codes generally correspond to each other both sides of the atlantic
These might help you out - from the BA Ultimate Guide;
http://www.flyertalk.com/forum/showpost.php?p=3354043
And from the AA Unofficial Guide which shows a comprehensive list further down;
http://members.shaw.ca/fewmiles/AA/recht/fares.html
Hope that helps!
(ps - R used to be Supersonic Class for BA )