Nagorno-Karabakh Republic (NKR)
Officially used: Armenian postage stamps from 20 February 1998
When Armenia and NKR have launched a joint issue on 20 February 1998, NAMAKANISH (Armenia) and ARTSAKHKAP (NKR) did swap 3.000 copies of their stamps to be able to offer both stamps to collectors.
But only their "own" stamps were valid for postal use in each country.
In contrast to NAMAKANISH, the ARTSAKHKAP could sell only small quantities of those stamps to collectors.
Six years later, more than 2.000 Armenian stamps still were left.
At the beginning of the year 2004, the almost permanent shortage of postage stamps in NKR resulted in ARTSAKHPOST's decision to put in use those Armenian stamps too.
Because NKR is not part of today's Armenia, that procedure was not postally correct and also politically explosive.
When the responsible officials became aware of that situation, they did stop the usage of Armenian stamps by a decision of Friday 2 April 2004.