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 PY021.04

  1. Py020.04-80
    Wns Number
    PY020.04
    Country / Post
    Paraguay
    Date of Issue
    October 22, 2004
    Subject
    MERCOSUR - Water, a resource in short supply - Felis pardalis
  2. Py021.04-80
    Wns Number
    PY021.04
    Country / Post
    Paraguay
    Date of Issue
    October 22, 2004
    Subject
    MERCOSUR - Water, a resource in short supply