I was asked to review this document for the ART area.  As a frequent user of JSON in HTTP APIs, and related specifications I am delighted to see this document reaching last call.

I think the word that sums up this document the best is "comprehensive". From the clearly defined terminology at the beginning of the document, examples included at every step of the way, clear separation of syntax and semantics of each concept introduced and the detailed treatment of the type system around functions, I found this document answered every question I might possibly have.

The only nit that I have is that the ABNF rule S is first used in section 2.1.1 and points to section 2.5 for details.  However, if you go to section 2.5 it does not define S because it was already defined in section 2.3.4.1.  It might be nice to have an appendix with a "collected" ABNF like RFC9110 does, so that any rule is easy to find.