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 SI005.18

  1. Si005.18-80
    Wns Number
    SI005.18
    Country / Post
    Slovenia
    Date of Issue
    January 26, 2018
    Subject
    Prominent Personalities - Ivan Cankar
  2. Si006.18-80
    Wns Number
    SI006.18
    Country / Post
    Slovenia
    Date of Issue
    January 26, 2018
    Subject
    Prominent Personalities - Ivan Vidav