YAML is fine at deeply-nested configs (where TOML kind of falls over), support for multi-line strings in a variety of formats is nice, and the ability to use re

YAML is fine at deeply-nested configs (where TOML kind of falls over), support for multi-line strings in a variety of formats is nice, and the ability to use references and anchors makes it good for things like defining a schema with reusable components. Mistakes were of course made with the "friendly" booleans (yes/no unquoted strings). The Docker Compose and OpenAPI formats, are good uses of YAML that would be cumbersome in any other format. Is HOCON better? Maybe. As far as I recall it doesn't have any affordance for multi-line strings, which I see as a valuable YAML feature. It does have its own merits, though, and is probability a better default than YAML in a lot of projects. But at least if you want an INI-like format, use TOML instead of an ad-hoc underspecified alternative.