On the documentation web page SQLite Query Language: Date And Time Functions, the phrases "IS0-8601" and "ISO-8601" are misspelled; they should be "ISO 8601".
Thanks again for this amazingly useful library. ~ Nayuki
So "ISO 8601" (with a space) does seem to be the official spelling. Nevertheless, "ISO-8601" seems to me to be a better way of rendering the identifier, as it makes it clear that a single identifier is intended. I'm inclined to leave this uncorrected.
If a dash in the middle is totally unacceptable, my second choice would be "ISO8601". That is less readable because it is difficult to distinguish the "O" in "ISO" from a zero. But it still seems better than separating ISO and 8601 into separate words.
Unless somebody can come up with a compelling reason why it should change, I think I'll just keep using my non-standard "ISO-8601" spelling.
There's still the issue of eye-ess-zero.