Each "article" in this category is a collection of entries about several stamp issuers, presented in alphabetical order. The entries are formulated on the micro model and so provide summary information about all known issuers. See the :Category:Compendium of postage stamp issuers page for details of the project. Obock Dates 1892 – 1894 Capital Obock Currency 100 centimes = 1 franc Refer Djibouti Occupation Francaise Refer Arad (French Occupation) Occupied Enemy Territories (TEO) Refer Syria (French Occupation) Oceanic Settlements Refer French Oceanic Settlements Oil Rivers Protectorate Dates 1892 – 1893 Capital Enugu Currency 12 pence = 1 shilling; 20 shillings = 1 pound Refer Nigerian Territories Oldenburg Dates 1852 – 1867 Currency 72 groat = 1 thaler Refer German States Olonetz Refer Aunus (Finnish Occupation) Olsztyn Refer Allenstein Oltre Giuba Refer Jubaland Oman Dates 1971 – Capital Muscat Currency 1000 baizas = 1 rial saidi Main Article Needed See also Muscat; Muscat & Oman OMF Refer Syria (French Occupation) ONF Castellorizo Refer Castelrosso (French Occupation) Orange Free State Dates 1868 – 1900 Capital Bloemfontein Currency 12 pence = 1 shilling; 20 shillings = 1 pound Refer Orange River Colony Orange River Colony Dates 1900 – 1907 Capital Bloemfontein Currency 12 pence = 1 shilling; 20 shillings = 1 pound Main Article Needed Includes Orange Free State Orchha Dates 1913 – 1939 Currency 12 pies = 1 anna; 16 annas = 1 rupee Refer Indian Native States Osterreich Refer Austria Ostland Dates 1941 – 1945 Currency 100 pfennige = 1 mark Refer German Occupation Issues (WW2) Ottoman Empire Refer Turkey Oubangui-Chari Dates 1922 – 1937 Capital Bangui Currency 100 centimes = 1 franc Main Article Postage stamps and postal history of Ubangi-Shari Includes Oubangui-Chari-Tchad See also Central African Republic; French Equatorial Africa Oubangui-Chari-Tchad Dates 1915 – 1922 Capital Bangui Currency 100 centimes = 1 franc Refer Oubangui-Chari References Bibliography Stanley Gibbons Ltd, Europe and Colonies 1970, Stanley Gibbons Ltd, 1969 Stanley Gibbons Ltd, various catalogues Stuart Rossiter & John Flower, The Stamp Atlas, W H Smith, 1989 XLCR Stamp Finder and Collector's Dictionary, Thomas Cliffe Ltd, c.1960 External links AskPhil – Glossary of Stamp Collecting Terms Encyclopaedia of Postal History Oa