I'm new to DNS and I'm trying to understand the DNS packet format. From what I understand, the authority section of a DNS packet gives information about servers that are authoritative for the domain name in question. From playing around with dig on UNIX (and from intuition), it seems as though records in the authority section are always NS records. However, I couldn't find confirmation of this anywhere. Is this correct? If not, what does it mean for an authority record to not be an NS record?