[geraldbauer]

You might look at JSON Next variants (if you remember - "classic" JSON is a subset of YAML), see https://github.com/json-next/awesome-json-next

My own little JSON Next entry / format is called JSON 1.1 or JSONX, that is, JSON with eXtensions, see https://json-next.github.io

[orthoxerox]

The list is missing http://www.relaxedjson.org/

Also, there's no explanation what <..-..> and <..+..> do.