Two letter ISO country codes and a few historical holdovers from the 1960s (e.g., arpa).
Document taken from Jim Spath's home page http://jim.spath.com/. The original document can be found here: http://www.bcpl.net/~jspath/isocodes.htmlHere are some intradocument shortcuts: a - f - k - p - u
ad Andorra, Principality of ae United Arab Emirates af Afghanistan, Islamic State of ag Antigua and Barbuda ai Anguilla al Albania am Armenia an Netherlands Antilles ao Angola aq Antarctica ar Argentina arpa Old style Arpanet as American Samoa at Austria au Australia aw Aruba az Azerbaidjan ba Bosnia-Herzegovina bb Barbados bd Bangladesh be Belgium bf Burkina Faso bg Bulgaria bh Bahrain bi Burundi bj Benin bm Bermuda bn Brunei Darussalam bo Bolivia br Brazil bs Bahamas bt Bhutan bv Bouvet Island bw Botswana by Belarus bz Belize ca Canada cc Cocos (Keeling) Islands cf Central African Republic cd Congo, The Democratic Republic of the cg Congo ch Switzerland ci Ivory Coast (Cote D'Ivoire) ck Cook Islands cl Chile cm Cameroon cn China co Colombia com Commercial cr Costa Rica cs Former Czechoslovakia cu Cuba cv Cape Verde cx Christmas Island cy Cyprus cz Czech Republic de Germany dj Djibouti dk Denmark dm Dominica do Dominican Republic dz Algeria ec Ecuador edu Educational ee Estonia eg Egypt eh Western Sahara er Eritrea es Spain et Ethiopia fi Finland fj Fiji fk Falkland Islands fm Micronesia fo Faroe Islands fr France fx France (European Territory) ga Gabon gb Great Britain gd Grenada ge Georgia gf French Guyana gh Ghana gi Gibraltar gl Greenland gm Gambia gn Guinea gov USA Government gp Guadeloupe (French) gq Equatorial Guinea gr Greece gs S. Georgia & S. Sandwich Isls. gt Guatemala gu Guam (USA) gw Guinea Bissau gy Guyana hk Hong Kong hm Heard and McDonald Islands hn Honduras hr Croatia ht Haiti hu Hungary id Indonesia ie Ireland il Israel in India int International io British Indian Ocean Territory iq Iraq ir Iran is Iceland it Italy jm Jamaica jo Jordan jp Japan ke Kenya kg Kyrgyz Republic (Kyrgyzstan) kh Cambodia, Kingdom of ki Kiribati km Comoros kn Saint Kitts & Nevis Anguilla kp North Korea kr South Korea kw Kuwait ky Cayman Islands kz Kazakhstan la Laos lb Lebanon lc Saint Lucia li Liechtenstein lk Sri Lanka lr Liberia ls Lesotho lt Lithuania lu Luxembourg lv Latvia ly Libya ma Morocco mc Monaco md Moldavia mg Madagascar mh Marshall Islands mil USA Military mk Macedonia ml Mali mm Myanmar mn Mongolia mo Macau mp Northern Mariana Islands mq Martinique (French) mr Mauritania ms Montserrat mt Malta mu Mauritius mv Maldives mw Malawi mx Mexico my Malaysia mz Mozambique na Namibia nato NATO (this was purged in 1996 - see hq.nato.int) nc New Caledonia (French) ne Niger net Network nf Norfolk Island ng Nigeria ni Nicaragua nl Netherlands no Norway np Nepal nr Nauru nt Neutral Zone nu Niue nz New Zealand om Oman org Non-Profit Making Organisations (sic) pa Panama pe Peru pf Polynesia (French) pg Papua New Guinea ph Philippines pk Pakistan pl Poland pm Saint Pierre and Miquelon pn Pitcairn Island pr Puerto Rico pt Portugal pw Palau py Paraguay qa Qatar re Reunion (French) ro Romania ru Russian Federation rw Rwanda sa Saudi Arabia sb Solomon Islands sc Seychelles sd Sudan se Sweden sg Singapore sh Saint Helena si Slovenia sj Svalbard and Jan Mayen Islands sk Slovak Republic sl Sierra Leone sm San Marino sn Senegal so Somalia sr Suriname st Saint Tome (Sao Tome) and Principe su Former USSR sv El Salvador sy Syria sz Swaziland tc Turks and Caicos Islands td Chad tf French Southern Territories tg Togo th Thailand tj Tadjikistan tk Tokelau tm Turkmenistan tn Tunisia to Tonga tp East Timor tr Turkey tt Trinidad and Tobago tv Tuvalu tw Taiwan tz Tanzania ua Ukraine ug Uganda uk United Kingdom um USA Minor Outlying Islands us United States uy Uruguay uz Uzbekistan va Holy See (Vatican City State) vc Saint Vincent & Grenadines ve Venezuela vg Virgin Islands (British) vi Virgin Islands (USA) vn Vietnam vu Vanuatu wf Wallis and Futuna Islands ws Samoa ye Yemen yt Mayotte yu Yugoslavia za South Africa zm Zambia zr Zaire zw Zimbabwe