I've also seen this done for C and modern C++. I believe it's done to suggest something (i.e. Rust is memory safe, C is usually fast, modern C++ is used to distinguish from the terrible old C++, Java runs on the JVM so it's relatively easy to use cross platform, Kotlin is for Java software that doesn't throw random null pointers every week, etc.)
The same tokens are also used for stuff that is designed to run on bare metal/containers/kubernetes/"""serverless""".