AFAIK calling DNS root the "." is quite recent phenomenon. I'm fairly old guy who did work with DNS about 35 years before retirement and what I recall from the

AFAIK calling DNS root the "." is quite recent phenomenon. I'm fairly old guy who did work with DNS about 35 years before retirement and what I recall from the beginning when I was reading my first copy of DNS and BIND somewhat quite soon it came out -92 I think the second chapter which describes DNS root "A null (zero-length" was already there. So a FQDN (Fully Qualified Domain Name) well known www.google.com the would be www.google.com."" where between the quotation denotes where the DNS root is shown. However, resolvers don't recognise that syntax. Don't be fooled by $ host www.google.com."" www.google.com has address 216.58.209.164 www.google.com has IPv6 address 2a00:1450:4026:802::2004 from the shell as it removes those double quotes. Using single quotes around shows how that fails and you can check it easily. $ host 'www.google.com.""' Host www.google.com."" not found: 3(NXDOMAIN) The way I learned to understand it the dot in DNS name is (it signifies) the DNS-tree separator, not part of the DNS name. A bit like in some languages (Pascal) use semicolon (;) a sentence separator not an end of sentence like it's in C and many it's practise adopted later. OK, here's an excerpt from DNS and BIND by Cricket Liu & Paul Albitz, O'Reilly ISBN 0-596-10057-6, Fifth Edition 2006 book which I still have a printed copy in my shelf and shows what I'm referring above. Chapter 2: How Does DNS Work, page 12, text after Figure 2-1 they write: "Domain Names Each node in the tree has a text label (without dots) that can be up to 63 characters long. A null (zero-length) label is reserved for the root. The full domain name of any node in the tree is the sequence of labels on the path from that node to the root. Domain names are always read from the node toward the root ("up" the tree), with dots separating the names in the path. If the root node's label actually appears in a node's domain name, the name looks as though it ends in a dot, as in "www.oreilly.com." (It actually ends with a dot—the separator—and the root's null label.) When the root node's label appears by itself, it is written as a single dot, "", for convenience. Consequently, some software interprets a trailing dot in a domain name to indicate that the domain name is absolute. An absolute domain name is written relative to the root and unambiguously specifies a node's location in the hierarchy. An absolute domain name is also referred to as a fully qualified domain name, often abbreviated FQDN. Names without trailing dots are sometimes interpreted as relative to some domain name other than the root, just as directory names without a leading slash are often interpreted as relative to the current directory. ... " I don't have old book copies any more, I've just this one with me.