Why doesn't "Cloudflare 1.1.1.1" compress root answers?

[Bjørn Mork <bjorn () mork no>]

At first I thought they had disabled compression:

 bjorn@miraculix:~$ dig . ns @1.1.1.1|grep SIZE
 ;; MSG SIZE  rcvd: 431
 bjorn@miraculix:~$ dig . ns @8.8.8.8|grep SIZE
 ;; MSG SIZE  rcvd: 239
 bjorn@miraculix:~$ dig . ns @9.9.9.9|grep SIZE
 ;; MSG SIZE  rcvd: 239


But then I noticed that they *do* compress other names:

 bjorn@miraculix:~$ dig net ns @1.1.1.1|grep SIZE
 ;; MSG SIZE  rcvd: 253
 bjorn@miraculix:~$ dig net ns @8.8.8.8|grep SIZE
 ;; MSG SIZE  rcvd: 253
 bjorn@miraculix:~$ dig net ns @9.9.9.9|grep SIZE
 ;; MSG SIZE  rcvd: 253


Which just makes it even more confusing.  What's so special about root?
Except for the obvious :-)



Bjørn