Rule 201.2b

Some spells and abilities refer to two or more objects with different names. Those objects have different names only if each of them has at least one name and no two objects in that group have a name in common. Example: A player controls Liliana’s Contract, which says, in part, “At the beginning of your upkeep, if you control four or more Demons with different names, you win the game.” That player controls three Demons with different names and a face-down creature with no name, with an effect making it a Demon. Because the four creatures include one with no name, those four creatures don’t count as four Demons with different names. The ability of Liliana’s Contract won’t trigger.