RFC 9839 and Bad Unicode
RFC 9839 and Bad UnicodeSearch Unicode is good. If you’re designing a data structure or protocol that has text fields, they should contain Unicode characters encoded in UTF-8. There’s another question, though: “Which Unicode characters?” The answer is “Not all of them, please exclude some.” This issue keeps coming up, so Paul Hoffman and I put together an individual-submission draft to the IETF and now (where by “now” I mean “two years later”) it’s been published as RFC 9839. It explains which characters are bad, and why, then offers three plausible less-bad subsets that you might want to use. Herewith a bit of background, but… Please · If you’re actually working on something new that will have text fields, please read the RFC. It’s only ten pages long,…
