Markdown Now Has a UTI in Apple’s Version 27 OSes

The third developer betas of Apple’s 27 OSes dropped today, and this new page in Apple’s developer documentation drew my attention — a built-in Uniform Type Identifier for Markdown data:

UTI: net.daringfireball.markdown

Conforms to: public.utf8-plain-text

I had previously recommended conforming to public.plain-text but stated that the text encoding should be UTF-8. I’ve updated my own recommendation to public.utf8-plain-text to enshrine the UTF-8 encoding. (Back in 2004 UTF-8 support was far from universal. Today it is.)

★ Monday, 6 July 2026