[dns-operations] Answer both Truncated and Authentic?

[Stephane Bortzmeyer]

Is it reasonable/legal to have both tc and ad?

% dig +noignore @8.8.8.8 ANY fr 

; <<>> DiG 9.7.3 <<>> +noignore @8.8.8.8 ANY fr
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46304
;; flags: qr tc rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;fr.				IN	ANY

;; Query time: 59 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu May 23 23:07:10 2013
;; MSG SIZE  rcvd: 31