DNS/RFC/7719について、ここに記述してください。
http://www.faqs.org/rfcs/rfc7719.html RFC 7719 - DNS Terminology
Glue records: "[Resource records] which are not part of the
authoritative data [of the zone], and are address resource records
for the [name servers in subzones]. These RRs are only necessary
if the name server's name is 'below' the cut, and are only used as
part of a referral response." Without glue "we could be faced
with the situation where the NS RRs tell us that in order to learn
a name server's address, we should contact the server using the
address we wish to learn." (Definition from [RFC1034],
Section 4.2.1)
A later definition is that glue "includes any record in a zone
file that is not properly part of that zone, including nameserver
records of delegated sub-zones (NS records), address records that
accompany those NS records (A, AAAA, etc), and any other stray
data that might appear" ([RFC2181], Section 5.4.1). Although glue
is sometimes used today with this wider definition in mind, the
context surrounding the [RFC2181] definition suggests it is
intended to apply to the use of glue within the document itself
and not necessarily beyond.最後の文が重要だ。"glue"がなにを指すかはその文書できちんと定義して使えと。
このことは次のin-bailiwickにも言えそう。
In-bailiwick:
(a) An adjective to describe a name server whose name is either
subordinate to or (rarely) the same as the zone origin. In-
bailiwick name servers require glue records in their parent zone
(using the first of the definitions of "glue records" in the
definition above).
(b) Data for which the server is either authoritative, or else
authoritative for an ancestor of the owner name. This sense of
the term normally is used when discussing the relevancy of glue
records in a response. For example, the server for the parent
zone "example.com" might reply with glue records for
"ns.child.example.com". Because the "child.example.com" zone is a
descendant of the "example.com" zone, the glue records are in-
bailiwick.
Out-of-bailiwick: The antonym of in-bailiwick.