Austria

• Red Mercury

Bermuda

• Perot provisional

Brazil

• Bull's Eye

British Guiana

Canada

• Canada 12d black
• Canada 2c Large Queen on laid paper - rarest Canadian stamp
• St. Lawrence Seaway invert

Cape of Good Hope

• Cape 4d black Triangle
• Cape 4d red error of color

Falkland Islands

• Falkland Islands HMS Glasgow error - wrong ship on a modern stamp

Finland

• Finland 20k black stamped envelope - most valuable postal stationery

German East Africa

• German East Africa 1 rupee used at Tabora

Germany

• Baden 9kr blue-green error of color
• Saxony 3pf red sheet
• Saxony 1/2g on light blue paper error
• Vineta provisional

Gibraltar

• Gibraltar 10c missing-value error

Hawaii

• Hawaiian Missionaries - first stamps of Hawaii

Honduras

• Black Honduras

India

• Scinde Dawk - first stamps of India
• India Queen Victoria invert

Italy

• Tuscany 3-lira ocher
• Italy General Balbo triptych

Jamaica

• Jamaica 1sh inverted-frame error

Japan

• Sutherland local boos
• Japan 500m Dragon invert

Macedonia

Sweden

Switzerland

• Basel Dove

Uganda

• Uganda Cowries - first stamps of Uganda, produced on typewriter

United Kingdom (Great Britain)

United States