On Sat, Jul 25, 2015 at 04:12:01PM -0400, John C Klensin wrote: > Christian, as I have told others, there was, between > approximately when the DNS came into use and when ICANN decided > to ignore it, a firm rule about such names. The rule was that > there would never been names (labels with delegation records) in > the DNS root longer than four characters, so one was free to > improvise with ".local", ".localhost", etc. No special rules > (or additional special rules) needed. Given what I know of operations at the time (and bearing in mind that I was not directly involved in TLD operations until the time ICANN was changing the rule), I believe the above to have been true. But it hasn't been true since 2001, and it seems to me that is long enough for us to say that the policy clearly changed. Anyway, it's not clear to me that this rule was ever actually written down, so it's hard to see how firm it was. RFC 1123 has some rules about the top level, but thost rules do not include the 4-character limit. RFC 1123 _does_ note that the DNS ought to work in a network not connected to the Internet, and talks about "local names", so it is clear there was an expectation that there would be some. RFC 1591 outlines the top-level domains, and it is silent on the 4-character rule. Anyway, it's quite clear that ICANN's new delegation decisions circa 2001 rendered 1591 obsolete (though why ICANN never published updates to 1591 is a mystery to me). Best regards, A (speaking as ever as an individual) -- Andrew Sullivan ajs@xxxxxxxxxxxxxxxxxx