OS-1	Its rarity is: A	It was used between: 1-31-36 and 8-?-45	Ink colours: Violet Blue Red Blue-green Green	Notes:
OS-1a	Its rarity is: A	It was used between: 9-29-82 and 12-13-82	Ink colours: Violet Red-violet Red	Notes: Used on Tin Can Mail Centenary covers
OS-2	Its rarity is: AA	It was used between: 10-?-35 and 3-13-44	Ink colours: Violet Black Blue Brown Blue-green Red	Notes:
OS-3	Its rarity is: DD	It was used between: 7-6-40 and 7-20-40	Ink colours: Black Blue-green	Notes:
OS-4	Its rarity is: DD	It was used between: 9-18-77 and 9-18-77	Ink colours: Not recorded	Notes:
OS-5	Its rarity is: A	It was used between: 9-29-82 and 12-13-82	Ink colours: Violet Red-violet Black	Notes: Used on Tin Can Mail Centenary covers
OS-6	Its rarity is: DD	It was used between: 9-28-? and 9-28-?	Ink colours: Not recorded	Notes:
OS-7	Its rarity is: DD	It was used between: 9-8-42 and 9-8-42	Ink colours: Not recorded	Notes:
OS-8	Its rarity is: C	It was used between: 4-19-37 and 12-21-46	Ink colours: Green Blue	Notes: Various dates