"Status": 2, // SERVFAIL - Standard DNS response code (32 bit integer).
"TC": false, // Whether the response is truncated
"RD": true, // Always true for Google Public DNS
"RA": true, // Always true for Google Public DNS
"AD": false, // Whether all response data was validated with DNSSEC
"CD": false, // Whether the client asked to disable DNSSEC
The RD (recursion desired) and RA (recursion available) flags aren't really relevant for DNS-over-HTTPS, but are included for completeness.
The comments above are not part of actual responses (JSON has no comment syntax in any case) but were added as explanatory text.
Do you think you would have noticed a separate section explaining these flags more readily than this example which you didn't?