Just want to point out that
Numerology is not the same as using numbers for code. Numerology refers to using numbers for divination, i.e. predicting the future, and the concept that certain numbers have a mystical significance. Using numbers for code is not at all forbidden by the Church, as it’s just another mode of communicating perfectly mundane things. The Church also doesn’t forbid numeric symbolism, such as using the number 4 to represent the Gospels, and the number 3 to represent the Trinity; again that is just a means of conveying mundane information.
(Point well taken, Ghosty! However, aside from divination and prophecy, it is apparent that the Church also does think that certain numbers have “mystical significance” too, wouldn’t you agree? Certainly 3 and 7 seem too. So there does seem to be a little bit of “blurring” between those significances allowed by the Church and those forbidden because of their use in numerology.)
The biggest clue that John is speaking of Nero, either directly or as a type, is that old manuscripts vary between using the numbers 666 and 616, and those numbers correspond to the two alternate spellings of Nero’s name in Hebrew. That’s a pretty HUGE coincidence! Given that fact, it’s possible that the
earliest versions of the text just had Nero’s name, and it was encoded afterwards according to Hebrew alphanumerics in order to hide the “incriminating” evidence during Nero’s campaign against the Christians (this last bit is just my personal speculation given the oddity of the “coincidence”).
Peace and God bless!