> In fact, the argument to use uppercase for normalization is that lowercase does not round trip. I believe neither upper or lower case round trips properly, w

> In fact, the argument to use uppercase for normalization is that lowercase does not round trip. I believe neither upper or lower case round trips properly, which is why Unicode invented fold case. Whenever this topic comes up I like to refer to one of my favourite talks on the topic: A Million Billion Squiggly Characters by Ricardo Signes: <https://www.youtube.com/watch?v=TmTeXcEixEg https://www.youtube.com/watch?v=TmTeXcEixEg>. Whilst nominally about Unicode handling in Perl, it's general enough that anyone using any language can learn something from it.