Sorry, it doesn't take much to start me singing showtunes. Yes, there is a significance to names. The use of a proper name implies a certain intimacy, whereas titles (like Springtrap and Puppet) is more neutral. Springtrap is less and less distant from the Puppet, but he does not want to call him by his birth name, Ian, as that ties him to the child Bob killed. (BTW, Springtrap knew Ian's name all along; it was in the news when the body was found.) Springtrap often adds a little more distance by giving the Puppet rude nicknames like Pinocchio and Casper. At first Springtrap was trying to goad a reaction out of the Puppet; lately it's more a habit than anything.The Puppet prefers to call people by their names, as that makes it more personal. He does that with the ghost children, and he would with the Nightmares if they had actual names. He wouldn't call BOB by his name unless it was offered to him; he's treading carefully, and doesn't want to set him off if at all possible. The Puppet doesn't care a whole lot what people call him, as long as they're talking to him.The one time Springtrap told someone else his name was after the Ghost Child had reached out to him sympathetically after Springtrap found out about the plan that lead to his demise. The Puppet told Springtrap the names of four of the ghost children, and some details about their lives, to impress on Springtrap that they are real people, not just faceless victims. I think those two scenes were the ones in which names were most significant.I hope this kinda answers your question.