ISO 3166-3 ni apa keta opagun ISO 3166 ti ISO tesiwejade lati soju awon amioro fun oruko awon orile-ede ti won ti je pipare kuro ninu ISO 3166-1.ItokasiISO 3166.. 
Ni akọọlẹ ninu isọ 3166-2, apa ọ̀págun isọ 3166 ti International Organization for Standardization (iṣọ) tẹjadesí to ṣètumọ̀ awọn ami fun orukọ awọn ipin koko koko awọn orilẹ-itọkasi.isọ 3166.. 