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Comment by DenisM | Hacker News Reader

I've been looking to generate support ticket numbers with built-in error correction, so they can be discussed over the phone with customers.

Didn't find any off-the-shelf implementations in .NET so I gave up for the time being.

I might just end up adding a checksum to the ticket# and then computing all possible permutations that still meet the checksum, and verify each match against the database of open tickets. Takes less space anyway.

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The EAN-13 standard is pretty close to what you need, giving single-digit error detection (tho not correction), and you can shorten it to the last 5 or 6 digits. As the last digit is the checksum, this gives you 4 or 5 digits of precision.

Back at my earlier workplace we used EAN-13s as product serial numbers. Generally in customer service we used the last 5 digits, with the leading ones being implied by product model.

If all I needed was detection I could just XOR all letters and append the result.

This doesn't detect a transposition error, which is somewhat common with humans. That's why in EAN-13 and similar codes, the checksum takes digits with varying weights.

doh. tank you!

You could use a random three word combo.

"Has there been any progress on sausage-biscuit-club?"

I'm worried about unintentional innuendo popping up. You never know which of the urban dictionary phrases this thing will generate...

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