If you look at the website for the wine you are translating, look at the top of the bottles. I am pretty sure they mean that special flat extra rim on top of these bottles. None of their wine bottles seem to be "geriffelt", though, they are all smooth. Maybe there is a better term for "Flanschrand", but I think this is what they mean. Good luck! And I think they should send you a bottle, so you have your information first hand :-)