"Yodan" is a name with many meanings. In Japanese, yodan doesn't mean just 4th level but can also be a digression or off-topic statement or it can be a prediction or guess. But if you use yodan to mean prediction you can only use it with negative verbs. For example, you can say "I can't yodan" but not "I can yodan". (Special thanks to Megumi Narita for all the detail.)
We're collecting yodans. If you know of anything or anyone called "Yodan" let us know at TheSirtons@ (add gmail.com to this address), and we'll add it to the list of Yodan namesakes.
Yodan Books and Art: After reading about this Haifa bookstore in the newspaper, we decided to look it up in the phone book and found a Yodan bookstore in Nahariya too. Is it a coincidence or is it a chain?
Rabbi Yodan: We went to the Tzipori National Park here in Israel and the park brochure (both the Hebrew and English versions) talks about a Rabbi Yodan. Nowhere in the park itself did we find any reference to Rabbi Yodan only Rabbi Yehuda Ha'Nassi. Well, we couldn't leave without visiting his grave in search of more clues. But there we found only a lot of books and a pile of crackers. Now if we'd found a pile of cat food we'd have been sure that this rabbi was really called Yodan. Guy thought maybe Yodan was the short form of Yehuda Ha'Nassi but a knowledgeable friend says that would be "Rin". So why this Yodan is Yodan (if this Yodan really is Yodan) is still a mystery to us.
Yodan Publishing: Publishers of Jewish books.