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.

HK023.10

Country / Post Hong Kong (PRC)
Date of Issue 28 September 2010
Primary theme Transportation (Rail) (Steam engines)
Subject Centenary of Railway Service in Hong Kong
Width 28.0 mm
Height 45.0 mm
Denomination 1.40 HKD
Number in set 7 (show set)
Layout/Format sheet of 25
Perforations 13.6 by 13.25
Stamp issuing authority Hongkong Post
Printer Joh Enschedé BV, the Netherlands
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