What type of token exactly is “var” in Java 10?

Question

In the last issue of Heinz Kabutz\'s newsletter, #255 Java 10: Inferred Local Variables, it is shown that var is not a reserved word in Java 10, because you can

Answer 1

According to JEP-286: Local-Variable Type Inference, var is

not a keyword; instead it is a reserved type name.

(Earlier versions of the JEP left room for implementing either as a reserved type name or as a context-sensitive keyword; the former path was ultimately chosen.)

Because it's not a "reserved keyword", it is possible to still use it in variable names (and package names), but not in class or interface names.

I would think the biggest reason for not making var a reserved keyword is backwards compatibility with old source code.