[dns-operations] Software that refuses an answer by QTYPE if it comes over plain UDP?

[Doug Barton]

Interesting question came up today, and while I think the answer is 
"No," I wanted to ask the smart kids. :)

Are there any name servers in play today that will only answer for a 
certain QTYPE if the query comes via either TCP, or UDP with cookies?

And a related question, is anyone thinking of developing some?

Doug