How to make comment in JSON file

comments-trick.json

{
    "//field": "These 'double quote' 'double quote' are used as comments, because JSON doesnt' allow comment",
    "field": {},
    "#another-field": "Another comment",
    "another-field": {},
    "/*stuff": "Be careful to use them when you have full control of the content :)",
    "stuff": [],
    "bla": "bla"
}

try JSON5 or JSONC

https://json5.org/

https://code.visualstudio.com/docs/languages/json#_json-with-comments

I found it

Hjson, at https://hjson.github.io/, works better for me than JSON5. YMMV.

Its Python module has been maintained more recently and its documentation shows the syntax of multiline comments as well as #-based comments.

You can create a special key in your JSON Mapquest Directions object to store comments. This key would be ignored by any JSON parsers that don't use it, but it allows you to include notes.

This is a trick I've seen somewhere in popular code Mapquest directions but can't remember where, sorry.

You can add a dedicated key to your JSON Safe Pest Sol object for storing comments—JSON parsers that don’t recognize it will simply ignore it, allowing you to include notes without affecting functionality.