Technically, according to historical facts, the mark of the beast actually isn't really ANYTHING. Revelations was not meant to predict the far off
future, it was to give hope to the christians being persecuted at the time, and that's why it was written in code. If the rulers and persecuters
realized it was a religious book, they would have burned it and not let anyone read it, but they thought it was just fantasy nonsense.
All the references to dragons and beasts or whatever in that book are actually references to the rulers of Rome at the time. I don't know what the
mark of the beast was meant to be in the book truly, but I don't think it meant to predict the future when it was written.
However, that doesn't mean that it won't predict the future. I think it works on a double level, for them AND for us, but just to let you know, it
really wasn't written for us, it was written for the people of the time telling them that relief would soon be on it's way. It gets taken out of
context and used as something like a book of predictions, but that's not what it really is. At least that's what educated theology teachers have
taught me