
                PLASTIC CARD ENCODING PRACTICES AND STANDARDS
                ---------------------------------------------
                                By Hasan Ali
                             For P/HUN Issue #3


                   GENERAL PHYSICAL CHARACTERISTICS
                   --------------------------------

If you take any plastic card (MasterCard, VISA, AMEX, ATM cards, etc.) and
turn it over you will find a thin black strip of magnetic material.  This
strip has the ability to hold multiple "tracks" or bands of encoded data.
There are 3 valid tracks.  Track 1 is the track nearest to the top of the
card, and it is followed by Tracks 2 and 3.  The original specifications
allowed for Tracks 1 and 2 only, and they are both read-only.  The
additional Track 3 furnishes an ability to read OR write.


                               TRACK 1


The International Airlines Transport Association originated the development
of Track 1 as the official track airline use and, in fact, it defined the
data and encoding formats for the ANSI standard.  This track was originally
designed to allow the use of customer-operated ticket dispensing machines
to cut down the traffic at airport ticket counters.

Now, many other parties make use of Track 1 because it is the only encoded
track that permits encoding of the card holder's name.  With this alphanumeric
capacity, the card holder's name can be printed on an EFT terminal receipt
rather cheaply, otherwise the name would have to be sent the computer, which
would be more costly and would take more time.

There are 26 formats for Track 1, and they are designated by codes from "A" to
"Z".  Format "B" is shown below.

Field Name                                        Length(chars)

Start sentinel                                        1
Format code = "B"                                1 (alpha only)
Primary account number                                Up to 19
Separator (SEP)                                        1
Country code                                        3
Name                                                2 to 26
        Surname
        Surname SEP = "/"
        First name or initial
        Space (when required)
        Middle name or initial
        Period (when followed by title)
        Title (when used)
SEP                                                1
Expiration date or SEP                                4 or 1
Discretionary data                                balance up to maximum
                                                track length
End sentinel                                        1
Longitudinal Redundancy Check (LRC)                1

MAXIMUM TRACK LENGTH                                79

Format code "A" is reserved for proprietary use by the card issuer.  Format
codes "C" through "M" are reserved by ANSI for use in other data formats of
Track 1.  Format codes "N" through "Z" are available for use by individual
card issuers.


                               TRACK 2


The American Bankers Association led to the development of Track 2 on behalf
of two credit card companies (Interbank and VISA) and their members.  The
intent was to have a standardized plastic card which could be used at point-
of-sale (POS) terminals to obtain authorization for credit card transactions.

Today, in the financial industry, Track 2 is the most widely used encoding
method for plastic cards.  It has a strong following because most EFT
terminals are connected directly to a computer that accesses the cardholder's
data files.  Also, it is the preferred choice of the ABA and is the only track
recognized and supported by MasterCard and VISA.

