Thanks! We're not planning to support inline comments at this time; this was a tradeoff we knew we'd have to make when we decided to use JSON.

Given the choice between supporting comments and supporting a wider variety of implementations/libraries ("plain" JSON as opposed to a comments-supporting variant), I think the latter is a more practical priority.

With that said, we'd like to add a standard way to add vendor-specific information to an MNX document — which is definitely a must-have, for applications that will use MNX as a native format — and I could see a comments-ish thing appearing in that form.

Regarding that examples page, I'm actually planning to do something along those lines anyway. The MusicXML docs and the MNX docs use the same system (a Django app), and the MusicXML part uses a custom XML tag to define "this part of the XML example should be highlighted in blue" (example: https://w3c.github.io/musicxml/musicxml-reference/examples/a...). It's on my to-do list to implement the same thing for the JSON version — which is essentially like inline comments(ish), if you squint.