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.


Country / Post United States of America
Date of Issue 27 January 2019
Primary theme National symbols (Flags)
Subject US Flag 2019
Width 24.0 mm
Height 23.0 mm
Denomination Forever
Number in set 1
Layout/Format self adhesive booklet of 20
Perforations imperforate by 11
Stamp issuing authority United States Postal Service