Fallback for the 2%

If you ask one hundred people to do a task (particularly one that involves following instructions or using a computer or both), figure that two of them will mess it up.

It doesn't matter if you use ALL CAPITAL LETTERS. It doesn't matter if your instructions are crystal clear. It doesn't matter if you ask them to sign a release. Two percent will mess it up. And it won't always be the same two percent either, so the idea of kicking the clueless out won't work.

Which means you only have two...