At Thu, 09 Jun 2005 08:03:03 -0500, 'wayne' wrote: > > So, in order to help this educational process, can someone give a > short paragraph that explains the differences between host names and > domain names, why the allowed characterset is different between the > two and when you should use one or the other? Really short answer: see RFC 1034 3.5 and RFC 1035 2.3.1. Slightly longer answer: Hostnames are a proper subset of DNS names. Hostnames have to fit the syntax defined in RFC 952 as amended by RFC 1123; DNS names only have to fit the much looser syntax defined in RFC 1035. You have to use hostnames when you're dealing with applications that say they're dealing with hostnames or which have their own syntax definitions which work out to be equivilent to the hostname syntax. Since most registries will not accept DNS names that don't comply with the hostname syntax, as a practical matter use of DNS names which are not hostnames is for the most part restricted to applications like the _prefix hack. Note that IDN deliberately encodes to DNS names which do fit the hostname syntax. As to "why?"...see the archives of the IDN WG for more details than you ever wanted, but I won't attempt to summarize because the opinion/fact ratio in this space is way too high. -- to unsubscribe send a message to namedroppers-request@ops.ietf.org with the word 'unsubscribe' in a single line as the message text body. archive: <http://ops.ietf.org/lists/namedroppers/>