It’s funny how some of the simplest software development decisions turn out to also be the toughest. One example is choosing the configuration file format for your application or service. Both JSON and YAML come to mind, of course. But if you need a config file format that’s easy to understand and relatively easy to parse into a data structure, you might consider TOML.
TOML, or Tom’s Obvious Minimal Language, was created chiefly for storing configuration data, with features that JSON and other formats lack. As an example, JSON doesn’t support inline comments.