Please refer to my original comment: > You can of course solve the same thing with JSON, but, well, YOU have to solve it. There is not a single well establish

Please refer to my original comment: > You can of course solve the same thing with JSON, but, well, YOU have to solve it. There is not a single well established convention across all languages/impls. The default behavior in many languages if a field is missing is to either panic, or replace it with a null pointer (which will just panic later, most likely).