(CNAME) A host's official name as opposed to an alias. The official name is the
first hostname listed for its Internet address in the hostname database,
/etc/hosts or the Network Information Service (NIS) map hosts.byaddr ("hosts"
for short). A host with multiple network interfaces may have more than one
Internet address, each with its own canonical name (and zero or more aliases).
You can find a host's canonical name using nslookup if you say
and then type a hostname.
candygrammar « canonical « Canonical Encoding Rules
canonical name » canonicity » C (ANSI) » can't