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 PY015.04

  1. Py015.04-80
    Wns Number
    PY015.04
    Country / Post
    Paraguay
    Date of Issue
    September 22, 2004
    Subject
    Paraguayan Railroad - Loc.151 (N.B.L.) - 1911 'Camello'
  2. Py016.04-80
    Wns Number
    PY016.04
    Country / Post
    Paraguay
    Date of Issue
    September 22, 2004
    Subject
    Paraguayan Railroad - Loc.104 (N.B.L.) - 1911 'El Coqueto'
  3. Py017.04-80
    Wns Number
    PY017.04
    Country / Post
    Paraguay
    Date of Issue
    September 22, 2004
    Subject
    Paraguayan Railroad - Loc.10 (Krupp) - 1886 'Sapucai'