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 NI006.04

  1. Ni005.04-80
    Wns Number
    NI005.04
    Country / Post
    Nicaragua
    Date of Issue
    June 30, 2004
    Subject
    America UPAEP - Protection of the Environment - Cerro Kilambé Natural Reserve
  2. Ni006.04-80
    Wns Number
    NI006.04
    Country / Post
    Nicaragua
    Date of Issue
    June 30, 2004
    Subject
    America UPAEP - Protection of the Environment - Bosawás-Rio Bocay's Biosphere Reserve