Hi again, Hilmar.

>>>Brief summary - and please note that I am no expert on this: GUID is a Windows
>>>function (API) that gives you a 16-byte value, unique in the World (if the computer
>>>has a network card), and very likely unique (if it doesn't).
>>
>>Hmmm. Sounds like IPv6 or something.
>
>No; the MAC address (serial number of the network card) is a 48-bit value;

Familiar with it. Upper bytes for maker of card, lower bytes the auto-increment :^)
number of the card, or something like that.

>this is incorporated into a 128-bit (16 byte) value, with this special function.
>It is totally unrelated to IP version 4 or 6, although the length happens to be
>the same as with IPv6.

Yep. I just say it sounded like it because they are messing around with the MAC
address of the NIC :^).

>The keys would used, most of the time, for internal use, IMO. Many programmers
>(but by no means all) agree that it is convenient to use, as the primary key,
>a value that is not seen by the user, thus freeing you of the need to change
>the primary key (and the corresponding foreign keys in other tables), when
>the user decides to change the coding system (client codes, city codes, whatever).

I like this idea, and I agree with you and the others. Keep that stuff out
of their face, and life will be a lot easier.

Regards,

Randall