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.

Stamps issued with MX021.09

  1. Mx021.09-80
    Wns Number
    MX021.09
    Country / Post
    Mexico
    Date of Issue
    September 14, 2009
    Subject
    Preservation of Polar Regions and Glaciers
  2. Mx022.09-80
    Wns Number
    MX022.09
    Country / Post
    Mexico
    Date of Issue
    September 14, 2009
    Subject
    Preservation of Polar Regions and Glaciers