Re: credit card conventional wisdom (fwd)

[Simon Spero <ses@tipper.oit.unc.edu>]

Further info:

  The AMEX digits aren't part of the standard info- someone I spoke to 
who started off as a grey box programmer said that he thought they were 
just process control. 

  Card-present/Card-not-present can be determined from info on the 
magnetic stripe; for visa cards, this info is stored in a three-digit 
checksum at the end of the discretionary info.

Card Imprints taken with no online authorisation are typically charged a 
transaction fee of 3-6%: with authorisation, 1.5-3%.  ATM card 
transactions  are charged at around $0.10 per transaction.


Simon