I know what are the supported languages in iBook author but I want to know what are the accepted languages by Apple.!?

I have created many iBook author books and most of them in English and French languages. Recently, I started creating books in different languages such Hebrew and Arabic. These two languages are supported by iBook Author app but I am not sure if they will be accepted by iBook store. I would like to know what are the accepted languages in iBook Store then I will stop doing the languages which are not accepted. For me, it is little bit confused from Apple (iBook store), They support the languages in their applications (such as Arabic, Hebrew) but then they do not accept specific languages after submitting to iBook store. I think Apple has a reason and plan for that but it is still hidden.

Please, if anyone can help me in this issue, I will be very grateful.

Thanks in advance.