If you don't speak English, don't post on English sections.
But there's no restrictions regarding that.
There is:
9. Discussions in the main boards must be in english. All other language discussions should be posted in the appropriate Local board.
You can argue up to what point bad English is still English, but it's obvious there is a line somewhere.
My bad from cutting your post. My actual thought was: No one restricts users to post in English boards even though their English is bad. Well unless it's so bad that no one understands anything.