Just a little bit of meta discussion: HN is generally good about this, but at the time I&#x27;m writing this, this comment is greyed out. It&#x27;s a reasonable question that I might have asked 5 years ago. They&#x27;re not bringing down the level of discourse, they just didn&#x27;t know something that is common knowledge. I feel like software people, if anyone, should be sympathetic towards people with holes in their knowledge, because we are confronted daily with how large the gulf is between our intellects and memories, and the extant complexity of the world we live in.