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.

LK003.11

Country / Post Sri Lanka
Date of Issue 30 January 2011
Primary theme Science & Technology (Physics & chemistry)
Subject International Year of Chemistry
Width 30.0 mm
Height 60.0 mm
Denomination 5.00 LKR
Number in set 1
Layout/Format sheet of 50
Perforations 13.5 by 14
Stamp issuing authority Department of Posts
Printer Department of Government Printing, Sri Lanka