Anthere-
I would not *exactly* call public mails to a list with probably over 100 registered users, tracked by Google, "semi-private exchanges" :-)
How many of our readers speak French? How about Chinese, or Croatian? The smaller the number, the more private the conversation. With French, I'd say it is at least semi-private.
First, unless that recently changed, this *public* list is *multilingual. We do not need authorisation to write another language than english here.
http://en.wikipedia.org/wiki/Wikipedia:Mailing_lists
"Posting in languages other than English is allowed, but English is preferred as it will reach the most diverse audience." This has always been my understanding of the way we want things to be.
The purpose of making the list multilingual is not to give people a loophole to have semi-private conversations, nor is it to somehow prove to ourselves how multilingual we are, and we certainly don't need a "French/ Russian/Esperanto post of the week" to remind us. The purpose of making the project-wide lists multilingual is to allow people to have discussions who otherwise could not. Such discussions can remain semi-private, if there is good reason for them to be so (e.g. people have difficulties speaking English and the matter is primary of interest to a handful of people), but in general, we should strive to either translate posts in both directions and thereby allow *open* communication, or to move discussions to e-mail or talk pages.
English is the most diversely spoken language in the world. It is the most widely learned second language and the second most widely spoken first language. Last but not least, it is the most widely spoken language on the Internet. Schools, the diminishing role of nation-states (EU etc.) and globalization further accelerate this development.
Using English is therefore the most friendly and internationalist approach possible. Of course many people dislike English for one reason or another, mainly because they associate it with a certain culture. But the best way to dissociate English from one particular culture is to use it.
Regards,
Erik