In short, comments in the form // ... or / * ... * / are not allowed in JSON, but you can have a special element in your JSON file called "_comment", for example, that will contain your comment. The JSON API endpoint must ignore this special JSON comment element. See an example of including comments in JSON below on the Content tab.
Can JSON contain comments?
Comments in the form //, #, or / * * / that are used in popular programming languages are not allowed in JSON. As a workaround, you can use a custom element in your JSON as shown in the JSON Comment Example. Your server and client must ignore this special element when processing the received JSON.
JSON Comment Example
In this JSON comment example, the "_comment" field contains the comment for your JSON. You can use any name for this element