I don't really like either format (I am not sure which is worse; both have significant problems). YAML has some problems (such as Norway problem and many other

I don't really like either format (I am not sure which is worse; both have significant problems). YAML has some problems (such as Norway problem and many other problems with the syntax), and JSON has different problems; and some problems are shared between both of them. Unicode is one problem that both of them have. Numbers are a problem in some implementations of JSON but it is not required. (Many other formats have some of these problems too, such as using Unicode, and using floating numbers and not integers, etc.) I think DER is better (for structured data), although it is a binary format, but it is in canonical form. I made up the TER format which is a text format which you can compile to DER, and some additional types which can be used (such as a key/value list type). While Unicode is supported, there are other (sometimes better) character sets which you can also use. (However, not all configuration files need structured data, and sometimes programs are also useful to include, and these and other considerations are also relevant for other formats, so not everything should use the same file formats anyways.)