United Kingdom 

Regional Issues - Northern Ireland

1st March 1967

Wilding stamp, as shown.

Catalogue numbers:

Michel GB-S 6
Stamp Number GB-S 6
Yvert et Tellier GB 433
AFA number GB 444
Unificato GB 433

Stanley Gibbons S 6 (XS26 - 2 phosphor bands reacting violet, watermark multiple crowns)