but we do: basic emacs org-mode file format is simple, intuitive, text-based and human-readable.
I don't think that qualifies as "commonly-accepted". It's not a bad format (for trees -- it doesn't look like it generalizes to DAGs or graphs), but a standard format might be helpful.
XML is a commonly-accepted tree file format.
XML is a meta-format.
Well, yeah, true. But all formats that are XML still fit my statement.
Yes thank you for down voting, what's incorrect about my statement?
I didn't downvote you, and I believe your comment was correct.