Long time ago, back in a day of Microsoft Office 95 and 97, I was contracted to integrate a simple API for a payment service provider.

They've sent me the spec, I read it, it was simple enough: 1. payment OK, 2. payment FAILED. Few hours later the test environment was up and happy crediting and debiting fake accounts. Then came the push to prod.

I worked with two other guys, we shut down the servers, made a backup, connected new provider. All looked perfectly fine. First customers were paying, first shops were sending their products... Until two days later it turned out the money isn't coming through even though all we are getting from the API is "1" after "1"! I shut it off. We had 7 conference calls, 2 meetings, 3 days of trying and failing. Finally, by a mere luck, I found out what's what.

You see, Microsoft, when you invent your own file format, it's really nice to make it consistent between versions... So that the punctuation made in Microsoft Word 97 that was supposed to start from "0" didn't start from "1" when you open the file in Microsoft Word 95.

Also, if you're a moron who edits documentation in Microsoft Word, at least export it to a fucking PDF before sending out. Please.