ISO 639:o

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|oaa || || ||B ||Y ||Orok||&nbsp;
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|oac || || ||B ||Y ||Oroch||&nbsp;
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|oar || || ||B ||A ||Aramaic, Old||&nbsp;
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|oav || || ||B ||T ||Avar, Old||&nbsp;
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|obi || || ||B ||Ö ||Obispeño||&nbsp;
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|obl || || ||B ||Y ||Oblo||&nbsp;
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|obm || || ||B ||A ||Moabite||&nbsp;
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|obo || || ||B ||Y ||Manobo, Obo||&nbsp;
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|obr || || ||B ||T ||Burmese, Old||&nbsp;
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|obt || || ||B ||T ||Breton, Old||&nbsp;
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|obu || || ||B ||Y ||Obulom||&nbsp;
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|oca || || ||B ||Y ||Ocaina||&nbsp;
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|occ || || ||B ||K ||Occidental||&nbsp;
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|och || || ||B ||A ||Chinese, Old||&nbsp;
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|oci ||oci ||oc ||M ||Y ||Occitan (post 1500); Provençal||&nbsp;
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|oco || || ||B ||T ||Cornish, Old||&nbsp;
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|ocu || || ||B ||Y ||Matlatzinca, Atzingo||&nbsp;
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|oda || || ||B ||Y ||Odut||&nbsp;
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|odk || || ||B ||Y ||Od||&nbsp;
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|odt || || ||B ||T ||Dutch, Old||&nbsp;
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|odu || || ||B ||Y ||Odual||&nbsp;
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|ofo || || ||B ||Ö ||Ofo||&nbsp;
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|ofs || || ||B ||T ||Frisian, Old||&nbsp;
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|ofu || || ||B ||Y ||Efutop||&nbsp;
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|ogb || || ||B ||Y ||Ogbia||&nbsp;
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|ogc || || ||B ||Y ||Ogbah||&nbsp;
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|oge || || ||B ||T ||Georgian, Old||&nbsp;
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|ogg || || ||B ||Y ||Ogbogolo||&nbsp;
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|ogn || || ||B ||Y ||Ogan||&nbsp;
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|ogo || || ||B ||Y ||Khana||&nbsp;
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|ogu || || ||B ||Y ||Ogbronuagum||&nbsp;
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|oht || || ||B ||A ||Hittite, Old||&nbsp;
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|ohu || || ||B ||T ||Hungarian, Old||&nbsp;
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|oia || || ||B ||Y ||Oirata||&nbsp;
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|oin || || ||B ||Y ||One, Inebu||&nbsp;
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|ojb || || ||B ||Y ||Ojibwa, Northwestern||&nbsp;
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|ojc || || ||B ||Y ||Ojibwa, Central||&nbsp;
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|ojg || || ||B ||Y ||Ojibwa, Eastern||&nbsp;
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|oji ||oji ||oj ||M ||Y ||Ojibwa||&nbsp;
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|ojp || || ||B ||T ||Japanese, Old||&nbsp;
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|ojs || || ||B ||Y ||Ojibwa, Severn||&nbsp;
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|ojv || || ||B ||Y ||Ontong Java||&nbsp;
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|ojw || || ||B ||Y ||Ojibwa, Western||&nbsp;
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|oka || || ||B ||Y ||Okanagan||&nbsp;
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|okb || || ||B ||Y ||Okobo||&nbsp;
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|okd || || ||B ||Y ||Okodia||&nbsp;
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|oke || || ||B ||Y ||Okpe (Southwestern Edo)||&nbsp;
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|okh || || ||B ||Y ||Koresh-e Rostam||&nbsp;
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|oki || || ||B ||Y ||Okiek||&nbsp;
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|okj || || ||B ||Ö ||Oko-Juwoi||&nbsp;
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|okk || || ||B ||Y ||One, Kwamtim||&nbsp;
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|okl || || ||B ||Ö ||Old Kentish Sign Language||&nbsp;
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|okm || || ||B ||T ||Korean, Middle (10th - 16th cent.)||&nbsp;
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|okn || || ||B ||Y ||Oki-No-Erabu||&nbsp;
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|oko || || ||B ||T ||Korean, Old (3rd - 9th cent.)||&nbsp;
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|okr || || ||B ||Y ||Kirike||&nbsp;
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|oks || || ||B ||Y ||Oko-Eni-Osayen||&nbsp;
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|oku || || ||B ||Y ||Oku||&nbsp;
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|okx || || ||B ||Y ||Okpe (Northwestern Edo)||&nbsp;
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|ola || || ||B ||Y ||Walungge||&nbsp;
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|old || || ||B ||Y ||Mochi||&nbsp;
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|ole || || ||B ||Y ||Olekha||&nbsp;
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|olm || || ||B ||Y ||Oloma||&nbsp;
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|olo || || ||B ||Y ||Livvi||&nbsp;
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|oma || || ||B ||Y ||Omaha-Ponca||&nbsp;
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|omb || || ||B ||Y ||Ambae, East||&nbsp;
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|omc || || ||B ||Ö ||Mochica||&nbsp;
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|ome || || ||B ||Ö ||Omejes||&nbsp;
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|omg || || ||B ||Y ||Omagua||&nbsp;
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|omi || || ||B ||Y ||Omi||&nbsp;
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|omk || || ||B ||Ö ||Omok||&nbsp;
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|oml || || ||B ||Y ||Ombo||&nbsp;
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|omn || || ||B ||A ||Minoan||&nbsp;
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|omo || || ||B ||Y ||Utarmbung||&nbsp;
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|omp || || ||B ||T ||Manipuri, Old||&nbsp;
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|omr || || ||B ||T ||Marathi, Old||&nbsp;
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|omt || || ||B ||Y ||Omotik||&nbsp;
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|omu || || ||B ||Ö ||Omurano||&nbsp;
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|omw || || ||B ||Y ||Tairora, South||&nbsp;
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|omx || || ||B ||T ||Mon, Old||&nbsp;
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|ona || || ||B ||Y ||Ona||&nbsp;
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|onb || || ||B ||Y ||Lingao||&nbsp;
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|one || || ||B ||Y ||Oneida||&nbsp;
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|ong || || ||B ||Y ||Olo||&nbsp;
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|oni || || ||B ||Y ||Onin||&nbsp;
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|onj || || ||B ||Y ||Onjob||&nbsp;
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|onk || || ||B ||Y ||One, Kabore||&nbsp;
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|onn || || ||B ||Y ||Onobasulu||&nbsp;
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|ono || || ||B ||Y ||Onondaga||&nbsp;
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|onr || || ||B ||Y ||One, Northern||&nbsp;
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|ons || || ||B ||Y ||Ono||&nbsp;
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|ont || || ||B ||Y ||Ontenu||&nbsp;
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|onu || || ||B ||Y ||Unua||&nbsp;
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|onw || || ||B ||T ||Nubian, Old||&nbsp;
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|onx || || ||B ||Y ||Onin Based Pidgin||&nbsp;
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|ood || || ||B ||Y ||Tohono O'odham||&nbsp;
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|oog || || ||B ||Y ||Ong||&nbsp;
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|oon || || ||B ||Y ||Önge||&nbsp;
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|oor || || ||B ||Y ||Oorlams||&nbsp;
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|oos || || ||B ||A ||Ossetic, Old||&nbsp;
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|opa || || ||B ||Y ||Okpamheri||&nbsp;
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|ope || || ||B ||A ||Persian, Old||&nbsp;
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|opk || || ||B ||Y ||Kopkaka||&nbsp;
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|opm || || ||B ||Y ||Oksapmin||&nbsp;
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|opo || || ||B ||Y ||Opao||&nbsp;
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|opt || || ||B ||Y ||Opata||&nbsp;
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|opy || || ||B ||Y ||Ofayé||&nbsp;
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|ora || || ||B ||Y ||Oroha||&nbsp;
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|orc || || ||B ||Y ||Orma||&nbsp;
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|ore || || ||B ||Y ||Orejón||&nbsp;
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|org || || ||B ||Y ||Oring||&nbsp;
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|orh || || ||B ||Y ||Oroqen||&nbsp;
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|ori ||ori ||or ||B ||Y ||Oriya||&nbsp;
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|ork || || ||B ||Y ||Orokaiva||&nbsp;
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|orm ||orm ||om ||M ||Y ||Oromo||&nbsp;
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|orn || || ||B ||Y ||Orang Kanaq||&nbsp;
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|oro || || ||B ||Y ||Orokolo||&nbsp;
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|orq || || ||B ||K ||Orcish||&nbsp;
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|orr || || ||B ||Y ||Oruma||&nbsp;
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|ors || || ||B ||Y ||Orang Seletar||&nbsp;
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|ort || || ||B ||Y ||Oriya, Adivasi||&nbsp;
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|oru || || ||B ||Y ||Ormuri||&nbsp;
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|orv || || ||B ||T ||Russian, Old||&nbsp;
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|orw || || ||B ||Y ||Oro Win||&nbsp;
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|orx || || ||B ||Y ||Oro||&nbsp;
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|orz || || ||B ||Y ||Ormu||&nbsp;
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|osa ||osa || ||B ||Y ||Osage||&nbsp;
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|osc || || ||B ||A ||Oscan||&nbsp;
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|osi || || ||B ||Y ||Osing||&nbsp;
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|oso || || ||B ||Y ||Ososo||&nbsp;
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|osp || || ||B ||T ||Spanish, Old||&nbsp;
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|oss ||oss ||os ||B ||Y ||Ossetian; Ossetic||&nbsp;
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|ost || || ||B ||Y ||Osatu||&nbsp;
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|osu || || ||B ||Y ||One, Southern||&nbsp;
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|osx || || ||B ||T ||Saxon, Old||&nbsp;
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|ota ||ota || ||B ||T ||Turkish, Ottoman (1500-1928)||&nbsp;
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|otb || || ||B ||T ||Tibetan, Old||&nbsp;
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|otd || || ||B ||Y ||Dohoi||&nbsp;
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|ote || || ||B ||Y ||Otomi, Mezquital||&nbsp;
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|oti || || ||B ||Ö ||Oti||&nbsp;
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|otk || || ||B ||T ||Turkish, Old||&nbsp;
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|otl || || ||B ||Y ||Otomi, Tilapa||&nbsp;
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|otm || || ||B ||Y ||Otomi, Eastern Highland||&nbsp;
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|otn || || ||B ||Y ||Otomi, Tenango||&nbsp;
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|otq || || ||B ||Y ||Otomi, Querétaro||&nbsp;
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|otr || || ||B ||Y ||Otoro||&nbsp;
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|ots || || ||B ||Y ||Otomi, Estado de México||&nbsp;
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|ott || || ||B ||Y ||Otomi, Temoaya||&nbsp;
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|otu || || ||B ||Ö ||Otuke||&nbsp;
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|otw || || ||B ||Y ||Ottawa||&nbsp;
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|otx || || ||B ||Y ||Otomi, Texcatepec||&nbsp;
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|oty || || ||B ||A ||Tamil, Old||&nbsp;
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|otz || || ||B ||Y ||Otomi, Ixtenco||&nbsp;
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|oua || || ||B ||Y ||Tagargrent||&nbsp;
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|oub || || ||B ||Y ||Glio-Oubi||&nbsp;
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|oue || || ||B ||Y ||Oune||&nbsp;
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|oui || || ||B ||T ||Uighur, Old||&nbsp;
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|oum || || ||B ||Ö ||Ouma||&nbsp;
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|oun || || ||B ||Y ||!O!ung||&nbsp;
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|owi || || ||B ||Y ||Owiniga||&nbsp;
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|owl || || ||B ||T ||Welsh, Old||&nbsp;
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|oyb || || ||B ||Y ||Oy||&nbsp;
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|oyd || || ||B ||Y ||Oyda||&nbsp;
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|oym || || ||B ||Y ||Wayampi||&nbsp;
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|oyy || || ||B ||Y ||Oya'oya||&nbsp;
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|ozm || || ||B ||Y ||Koonzime||&nbsp;
|}