The World Association for the Development of Philately (WADP) and the Universal Postal Union (UPU) jointly conceived and developed the WADP Numbering System - WNS, which was launched on 1 January 2002.

BG009.08

Country / Post Bulgaria
Date of Issue 25 April 2008
Primary theme Aviation (Aviation Pioneers)
Subject History of Military Aviation - 95th Anniversary of birth of General Stoyanov and 90th Anniversary of birth of Captain D. Spisarevski
Width 55.0 mm
Height 30.0 mm
Denomination 0.55 BGL
Number in set 2 (show set)
Layout/Format sheet of 20
Perforations 13 by 13
Stamp issuing authority Bulgaria Posts PLC
Printer Bulgarian Philately and Numismatics