Technet reference: http://technet.microsoft.com/en-us/library/cc754345

and also: http://blogs.technet.com/b/isrpfeplat/archive/2010/09/23/dns-scavenging-internals-or-what-is-the-dnstombstoned-attribute-for-ad-integrated-zones-dstombstoneinterval-dnstombstoned.aspx

and: http://blogs.technet.com/b/networking/archive/2008/03/19/don-t-be-afraid-of-dns-scavenging-just-be-patient.aspx

tracking DNS records deletion: http://blogs.technet.com/b/networking/archive/2011/08/17/tracking-dns-record-deletion.aspx

dnscmd syntax: http://technet.microsoft.com/en-us/library/cc784399(v=ws.10).aspx

extract1: “For resource records that you add manually, a time-stamp value of zero is used, indicating that these records are not affected by the aging process ”

extract2: “In the case of changing a zone from standard primary to Active Directory-integrated, you may want to enable scavenging of all existing resource records in the zone. To enable aging for all existing resource records in a zone, you can use the AgeAllRecords command, which is available through the dnscmd command-line tool.”

extract3: “Aging and scavenging properties that are configured at the DNS server properties that apply only to Active Directory Domain Services (AD DS)–integrated zones. For standard primary zones, you must set the appropriate properties at the applicable zone. “