3867.	[func]		"rndc nta" can now be used to set a temporary
			negative trust anchor, which disables DNSSEC
			validation below a specified name for a specified
			period of time (not exceeding 24 hours).  This
			can be used when validation for a domain is known
			to be failing due to a configuration error on
			the part of the domain owner rather than a
			spoofing attack. [RT #29358]