Question about Mapping DB Recursion Depth on Fiasco.OC

Hello, as far as I understand, the mapping database consists of a treemap with an entry for each superpage. Each entry points to an array describing the page's mappings (mapping tree). Each element of this mapping tree either represents a mapping or stores the address of a treemap, if the superpage has been splitted into pieces with a size of the next smaller valid page size. Is it correct that an element of a mapping tree references another treemap only in case the page has been spllitted and therefor the maximum recursion depth is limited by the amount of valid page sizes? Christoph