Kosovo, which won its battle to become a DXCC entity earlier this year, appears to have another fight on its hands. International Telecommunication Union (ITU) Secretary-General Houlin Zhao has determined that the Z6 call sign prefix was never allocated to Kosovo. The Secretary-General issued his finding in the wake of a March 16 inquiry from Serbia, from which Kosovo declared independence 10 years ago, the last piece of the former Yugoslavia to do so. Serbia has continued to reject Kosovo’s secession.

“ITU has not allocated call sign series Z6 to any of its member states,” Houlin Zhou said. “Consequently, the utilization of call signs series Z6 by any entity without a formal allocation and consent of the ITU represents an unauthorized and illegal usage of this international numbering resource.”

Kosovo is not an ITU member state and is therefore not eligible to receive a call sign block allocation from the ITU.

Houlin Zhou also informed the International Amateur Radio Union (IARU) that the ITU had not authorized use of the Z6 prefix, and he asked the IARU not to include Z6-prefix call signs on its website, where they have appeared since the 2015 admission of Shoqata e Radio Amatoreve te Kosoves (SHRAK) as an IARU member-society. An ITU sector member, the IARU complied with the request and advised SHRAK.

Kosovo joins a short list of DXCC entities where radio amateurs use “unofficial” call sign prefixes. The list also includes Western Sahara (S0) and the Sovereign Military Order of Malta (1A).

Earlier this year, in Mission Goodwill Kosovo, the IARU member-society SHRAK’s headquarters station Z60A mounted a massive special event operation to celebrate Kosovo’s addition to the DXCC List, as well as its 10th anniversary of independence.

In July 2010, the International Court of Justice (ICJ) found that Kosovo’s declaration of independence from Serbia did not violate international law. Relations between the two nations have become less hostile in recent years, but Serbia likely would oppose any move on Kosovo’s part to normalize the Z6 call sign block with the ITU.

Avenues to resolve the call sign prefix issue for Kosovo all are fraught with possible roadblocks. In addition to possible action at World Radiocommunication Conference 2019 — which could run into Serbian opposition — Kosovo’s telecommunications regulator could decide to assign call signs from a block the ITU is not using.