Forum policy question - foreign language posts

What would happen if I start a thread or reply to a thread using a foreign language throughout that post?

Would the post be deleted, or just left to its own devises so that whoever understands it can respond and whoever cannot understand it can just ignore it?

I guess it depends on the necessity of what you're trying to get across. As is probably obvious, posts in languages that we can potentially not be able to understand are open for abuse by unscrupulous users and the like. Out of curiousity, what situations would you find yourself in that using another language would be beneficial in comparison to using English?

Hard question.

English only. The mass majority of forum users use either English as their first language (UK,USA,Aussies) or use it as their second language (most European countries)

There is other forums that cater for everyone else. Not fair maybe but I for one wouldn't want to see threads started in a language I can't read. Too many possibilities for bad behavior.

Most forums that do not openly offer international/foreign language support, usually in designated forums, remove them because they have no accountability. If none of the moderation staff can read them, they can not be moderated.

Is there any situation that necessitates the use of a foreign language that can not be initiated in English on the forum proper, and swapped to the other language in PM's or relegated to an alternate medium such as an IRC chatroom when multiple people are involved?

Note that the above I've said is all personal speculation and not any kind of official forum policy. I don't believe I've ever seen this issue come up before, though a marginally similar issue has.