Wouter, in my german version of the racing rules 1985-1988 in the introduction they say that this is the first version to use "Steuerbord-Wind" (wind from starboard) instead of "Backbord-Bug" (tilted to port) in the rules. So if you can get a hand of an older version you probably find the "port over starboard" version of the rule. This was done to adapt the german version (where backbord-bug vor steuerbord-bug was common usage) to the english version. Interesting enough that this subject still causes confusion...