BalfML, my own markup language, is now available to view on my GitHub as a formal specification.
Whilst the specification is clear and provides some clarity as to what the language context will look like, it's is far from finished. There are plans to update the formal specification and indeed the markup as I begin to develop Java, Python and C# libraries that will parse the data to the correct format.
The formal specification of BalfML is similar to that of the specificationless INI format and the TOML markup language. However, BalfML has a few additional data types and features.
I will soon build this in Java as well as for ZPE.
I also intend on using this as a configuration format for ZPE soon enough.