M. Adam Davis wrote:
> Serial Number:
>
> AAx-xBBx-xCC
>
> AA, BB, CC are letters
> xxxx are numbers.
> dashes are dashes - spacing to group the numbers for readability.

Or you could go for total obfuscation and let a computer figure it out.
Let's say you want to identify the manufacturing date down to the week.
2008 to 2099 is 92 years, there are 52 weeks, let's say you want to support
100 models, a 6 bit checksum value to detect garbled serial numbers, and at
least 100000 units per year per model.

92 x 52 x 100 x 64 x 100000 = 3e12

There are 36 common digits and upper case letters, but let's say you exclude
"I", "O", and "S" to avoid confusion with 1, 0, and 5.  When you enter a
serial number into the computer, it automatically converts those letter to
the digits.  That leave 33 choices per digit.  8 digits gives you 1.4e12
combinations, or about half of the number above.  You can use 9 digits or
live with 50000 units per model per year, etc.


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