[doomlaser]

I created a shareware Tetris clone for OS X in the mid 2000s and provided my cell number in the readme. I'd get a trickle of calls from all over the world at all times of day. That's where I learned never to have a serial number generator that included the number 0 since it looks so close to the letter 0.

It was weird to be out and about and suddenly get a tech support call, but people were usually really nice.

[Terr_]

> the number 0 since it looks so close to the letter 0.

Just throwing this out there in case the problem comes up again: https://en.wikipedia.org/wiki/Base58

[SyneRyder]

It's also worth skipping out the letters S and number 5, the letter G and number 6, and the letter B and number 8. I also omit vowels to avoid accidentally creating words in serial codes.

[bonesss]

I autogenerate passwords exclusively using lower case 'L's, the letter i in both cases, the number 1, and pipe characters.

[gspetr]

There's room for improvement. What about the "!"? Gotta catch those folks with poor eyesight.

[jimktrains2]

Also Base32, which has more out-of-the-box support:

https://en.wikipedia.org/wiki/Base32#Crockford.27s_Base32

[mark-r]

That's a good start, but if the string is meant to be typed by hand it would be better to be case insensitive. Some kind of base 32 encoding would be appropriate.

[holografix]

I remember back in the early days of shareware and freeware apps and games where the developer would ask for a postcard if you enjoyed the app!

If I ever develop something really small and useful one day I’d love to get post cards from around the world!

[majewsky]

I actually thought about adding a similar remark to my programs' READMEs just today, but I don't particularly want my snail-mail address floating around the internet any more than necessary. (Maybe I'll get a postbox, if that's not too expensive.)

[cpv]

Still can be found https://news.ycombinator.com/item?id=15709248

[IncRnd]

The letters I, O and Q are not allowed in automobile VIN codes for the same reason.

[astura]

It's also advisable to omit vowels entirely to avoid generating offensive words.

[cdubzzz]

What clone? I was involved with Quinn on OS X back in the day until we got a C&D from The Tetris Company.

[doomlaser]

Descender http://web.archive.org/web/20081225163958/http://www.sloppyd...

[cdubzzz]

Nice, looks like it was around about same time as Quinn - https://web.archive.org/web/20110805131134/http://www.simonh...

Did you ever hear from TTC?

[doomlaser]

Managed to elude that, though I did meet Pajitnov at GDC years later.

[contingencies]

You can also use a checksum like in IBAN, I have implemented some auto-detection of mistranscribed input based upon that over here: https://github.com/globalcitizen/php-iban