User blog comment:Pheopheonix1234/Assassin's Creed 3/@comment-203.143.249.234-20110919024827/@comment-4181833-20110919215019

No, they are simply not numbered entries. It's technically number 4 (in the main series). They expand on Ezio's story because apparently he has a very important role in the history of Assassin's Creed. More so than we know so far.