alt Hacker NewsCouldn't help riffing off on a tangent from the title (since the article is about diagramming tools)...
Dylan Beattie has a thought-provoking presentation for anyone who believes that "plain text" is a simple / solid substrate for computing: "There's no such thing as plain text" https://www.slideshare.net/slideshow/theres-no-such-thing-as... (you'll find many videos from different conferences)
Haven't watched the videos yet, but from the slides, it looks like part of the issue he was talking about was encodings (there's a slide illustrating UTF-16LE ve UTF-16BE, for example). Thankfully, with UTF-8 becoming the default everywhere (so that you need a really good reason not to use it for any given document), we're back at "yes, there is such a thing as plain text" again. It has a much larger set of valid characters, but if you receive a text file without knowing its encoding, you can just assume it's UTF-8 and have a 99.7% chance of being right.
FINALLY.