It is erroring on `*.html`, which is reasonable because `.html` is an invalid anchor identifier, though the error is not that useful. The parsing of the unquoted version numbers also seems to be "correct", in that things that look like numbers are supposed to be parsed as numbers.

And I don't much like them as an end-user either, at least where there's a decent operator as an alternative.

(The definition of "decent" starts with "good documentation", looking at you Prometheus operator.)

And yes let’s not even get into the state of off the shelf charts.

2. The unquoted aliases (*.html, *.png) are invalid: that yq errors on them is the correct output. (I.e., if you want those as literal strings, they MUST be quoted.)

"The plain (unquoted) style has no identifying indicators and provides no form of escaping. It is therefore the most readable, most limited and most context sensitive style."

Which reads to me that they expected people to treat the plain style as a convenience that had notable downsides.

Edit: Note that this is the "plain" style, where there's also single and double quoted styles.

Maybe, but unquoted strings not being the right choice for all use cases (or, similarly, structure-by-indentation not being) doesn’t show that, since YAML supports unquoted and quoted strings, and supports both indent-sensitive “block style” and delimiter-based “flow style”.