Tav means “Mark, sign, cross.” An X or cross was the ancient Phoenician form of the letter Tav. Ancient Rabbis called Tav “the seal of truth, god, creation”. A signature is the mark one makes that states law or truth. We sign a document with our name to indicate that it is true and binding.
The ATM uses an electronic signature or mark called a PIN (Personal Identification Number). This signature is kept in the person’s head. This fulfills prophecy.
Revelation 13:16
And he causeth all the people, small and great,
rich and poor, free and slave,
to be given a mark
in their right hands or in their foreheads,
Revelation 13:17
And that no man might buy or sell,
save he that had the mark,
or the name of the beast,
or the number of his name.