Summary

  • Yugoslavia’s .YU code left the active ISO list in 2003, but the domain remained in the DNS root until 2010 because registry control and user dependencies had to move on different clocks.
  • A reserved-name migration into .RS, a temporary RNIDS caretaker and a separate shutdown of the .YU service preceded the root-zone change; neither a replacement code nor a root edit could update every address already in use.

A label can change before an address stops working

The first .YU delegation dates to 1989. After Yugoslavia broke up in the early 1990s, the original operators were no longer based there. In 1994, management shifted to faculty members at the University of Belgrade, operating as YUNET. The code’s political referent and the people running its name service had already separated before the later retirement debate began. IANA’s 2007 account of the .RS and .YU decisions traces that history.

In July 2003, ISO changed the code for the Serbia–Montenegro union from YU to CS. The .YU operator told IANA that a Montenegrin referendum could dissolve the union, so IANA did not push for an immediate move to .CS. That pause mattered: a two-letter code was an input to the root-zone process, not a decision by IANA about which state existed. RFC 1591 describes IANA’s coordination role and the use of ISO country codes; ICANN’s 2006 retirement discussion paper also said there was no formally defined process for retiring a ccTLD once its ISO code was no longer active.

Two successor codes needed one bridge

Montenegro’s May 2006 referendum supported independence; Serbia and Montenegro declared independence the following June. The ISO revision of 26 September removed CS and added ME for Montenegro and RS for Serbia. New root delegations could now be considered, but the old .YU zone still served users on both sides of the split.

The 11 September 2007 ICANN Board decision paired the new .RS delegation with a temporary redelegation of .YU to Serbia’s National Registry of Internet Domain Names, RNIDS. RNIDS would act as caretaker, report progress every six months, and work with Montenegro’s government toward a 30 September 2009 removal deadline. The agreed destination was .RS for Serbia and .ME for Montenegro. The decision explicitly placed country identification with ISO rather than ICANN; the registry’s job was to execute a transition under that external code system, not settle the political question.

The 2007 plan directed registrations in the .CG.YU, .MN.YU and .CG.AC.YU subdomains, used by Montenegrin entities, toward .ME; the rest of .YU was eligible to move to .RS. RNIDS also undertook to stop accepting new .YU registrations when the .RS sunrise period ended. After that point, the old zone would be maintained only so existing holders could modify or delete their registrations. The transition closed new inflow before it removed the remaining names.

The migration gave existing .YU holders a first claim on corresponding .RS names. For six months after .RS began operating, those holders could redeem reserved names; unclaimed reservations expired in September 2008, when general .RS registration opened. The registry then identified inactive .YU names: 2,769 were considered active, while the rest were removed in March 2009. From March through May, 1,236 holders appealed for reinstatement. These are separate counts from the later number still delegated, so they should not be read as a one-to-one account of successful transfers.

The root was only one place that still remembered .YU

By June 2009, 4,266 .YU domains remained delegated, down from 32,772. There were 26,294 .RS registrations; only about 200 of the remaining .YU domains lacked a matching .RS name. A matching name did not erase every dependency on the old address. RNIDS cited mailing-list subscriptions, logins and password-recovery mail, URLs saved in software and phones, contact addresses at other top-level domains, and pages still indexed by search engines. Google’s reported .YU index fell from 69 million pages in September 2007 to 6.2 million in June 2009.

The figures show how much reference material persisted; they do not measure how many people lost service.

In September 2009, the Board extended the deadline to 30 March 2010 after RNIDS asked for more time to finish the transition. The record says the request gave no specific justification beyond lingering .YU use, then lists the operational dependencies. RNIDS switched off the .YU service at midnight GMT+1 on 30 March. The delegation left the DNS root zone on 1 April, in serial update 2010040100. Those were two distinct acts: the registry stopped serving the zone before the root’s delegation record was removed.

A retirement without a complete retirement rule

The 2006 discussion paper framed the missing process in advance. A 2011 ccNSO working-group report later found no documented retirement procedure and treated the .YU decisions as an inferred practice: an active, registered namespace could be given a finite migration period and progress reporting. That report is a retrospective analysis, not a new rule that governed the 2007 decision.

The evidence supports a narrow conclusion. ISO supplied the code-status trigger; ICANN and IANA coordinated the root and delegation decisions; RNIDS and Montenegro’s government carried the migration; registrants and the services that stored their addresses determined how much practical work remained. Removing .YU from the root could end ordinary resolution, but it could not rewrite old mail-list memberships, account records or bookmarks. The official reports document the transition and its remaining references, not the resulting cost or loss for each user.

Sources and limits