They only write their first names in the guest book: Boris, Demetrius etc..........
Cut it out. You are making me laugh!
In a high class establishment like Mar a Lago they would sign in with name and patronymic, Ivan Michailovich, Boris Denisovich, Pyotr Illych, or Vladimir Vladimirovich [shhhhh - his plane is at the dark end of PBIa in a private hanger]