User blog comment:WonderBuono!/H!P Wiki Newsletter: December 2013/@comment-6092594-20131206003533/@comment-131168-20131206011958

Yeah, I've tinkered with it a little, too. It has limits on number of items (I think it's 4 top level, 7 in the second level, 10 in the third and final level), as well as width/text length limits for the first two levels since they're placed side by side.