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 CH025.05

  1. Ch025.05-80
    Wns Number
    CH025.05
    Country / Post
    Switzerland
    Date of Issue
    September 06, 2005
    Subject
    Subtractive synthesis
  2. Ch026.05-80
    Wns Number
    CH026.05
    Country / Post
    Switzerland
    Date of Issue
    September 06, 2005
    Subject
    Additive synthesis