No data types on that level, much like in XML.
Now above that level there is several ways to differentiate between them.
The simplest pragmatic way is a kind of type inference: if a text parses as a number, it's a number, if it's "true" or "false", it's a boolean. Otherwise it's a string. If you know the implicit schema of your data then this will be sufficient to get the job done.
Otherwise you employ a separate schema -- JC in particular has per-parser schemas anyway, so that's covered in this case. If it wouldn't, you'd need to write a schema yourself.
Or you do "syntax-driven" data types, similar to JSON, e.g. strings start w/ "'".
Here is a shitty demo: https://jevko.github.io/interjevko.bundle.html
It shows schema inference from JSON and the schemaless (syntax-driven) flavor.
Jevko itself is stable and formally specified: https://github.com/jevko/specifications/blob/master/spec-sta...
It's very easy to write a parser in any language (I've written one in several) and from there start using it.
However, I am still very much working on specifications for formats above Jevko. I have some recent implementations of the simplest possible format which converts Jevko to arrays/objects/strings:
* https://github.com/jevko/easyjevko.lua
* https://github.com/jevko/easyjevko.js
The schema-driven format that was used in the demo is implemented here: