| AD | Andorra | * |
| AE | United Arab Emirates | * |
| AF | Afghanistan | |
| AG | Antigua and Barbuda | * |
| AI | Anguilla | |
| AL | Albania | |
| AM | Armenia | * |
| AN | Netherland Antilles | |
| AO | Angola (Republic of) | |
| AQ | Antarctica | |
| AR | Argentina | * |
| 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) Isl. | |
| CF | Central African Rep. | |
| CG | Congo | |
| CH | Switzerland | * |
| CI | Ivory Coast | |
| CK | Cook Islands | |
| CL | Chile | * |
| CM | Cameroon | |
| CN | China | * |
| CO | Colombia | * |
| CR | Costa Rica | * |
| 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 | * |
| EE | Estonia | * |
| EG | Egypt | * |
| EH | Western Sahara | |
| ER | Eritrea | |
| ES | Spain | * |
| ET | Ethiopia | * |
| FI | Finland | * |
| FJ | Fiji | |
| FK | Falkland Isl.(Malvinas) | |
| FM | Micronesia | * |
| FO | Faroe Islands | |
| FR | France | * |
| FX | France (European Ter.) | |
| GA | Gabon | |
| GB | Great Britain (UK) | * |
| GD | Grenada | |
| GE | Georgia | |
| GF | Guiana (Fr.) | |
| GH | Ghana | |
| GI | Gibraltar | |
| GL | Greenland | |
| GM | Gambia | |
| GN | Guinea | |
| GP | Guadeloupe (Fr.) | |
| GQ | Equatorial Guinea | |
| GR | Greece | * |
| GS | South Georgia and South Sandwich Islands | |
| GT | Guatemala | * |
| GU | Guam (US) | * |
| GW | Guinea Bissau | |
| GY | Guyana | * |
| HK | Hong Kong | * |
| HM | Heard & McDonald Isl. | |
| HN | Honduras | |
| HR | Croatia | * |
| HT | Haiti | |
| HU | Hungary | * |
| ID | Indonesia | * |
| IE | Ireland | * |
| IL | Israel | * |
| IN | India | * |
| IO | British Indian O. Terr. | |
| IQ | Iraq | |
| IR | Iran | |
| IS | Iceland | * |
| IT | Italy | * |
| JM | Jamaica | * |
| JO | Jordan | * |
| JP | Japan | * |
| KE | Kenya | * |
| KG | Kyrgyz Republic | |
| KH | Cambodia | |
| KI | Kiribati | |
| KM | Comoros | |
| KN | St.Kitts Nevis Anguilla | |
| KP | Korea (North) | |
| KR | Korea (South) | * |
| KW | Kuwait | * |
| KY | Cayman Islands | |
| KZ | Kazachstan | |
| 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 | Moldova | |
| MG | Madagascar | |
| MH | Marshall Islands | |
| MK | Macedonia (former Yug.) | |
| ML | Mali | |
| MM | Myanmar | |
| MN | Mongolia | |
| MO | Macau | |
| MP | Northern Mariana Isl. | |
| MQ | Martinique (Fr.) | |
| MR | Mauritania | |
| MS | Montserrat | |
| MT | Malta | * |
| MU | Mauritius | |
| MV | Maldives | * |
| MW | Malawi | |
| MX | Mexico | * |
| MY | Malaysia | * |
| MZ | Mozambique | |
| NA | Namibia | |
| NC | New Caledonia (Fr.) | |
| NE | Niger | |
| NF | Norfolk Island | |
| NG | Nigeria | |
| NI | Nicaragua | * |
| NL | Netherlands | * |
| NO | Norway | * |
| NP | Nepal | |
| NR | Nauru | |
| NU | Niue | |
| NZ | New Zealand | * |
| OM | Oman | |
| PA | Panama | * |
| PE | Peru | * |
| PF | Polynesia (Fr.) | |
| PG | Papua New Guinea | |
| PH | Philippines | * |
| PK | Pakistan | * |
| PL | Poland | * |
| PM | St. Pierre & Miquelon | |
| PN | Pitcairn | |
| PR | Puerto Rico (US) | |
| PT | Portugal | * |
| PW | Palau | |
| PY | Paraguay | * |
| QA | Qatar | |
| RE | Reunion (Fr.) | |
| RO | Romania | * |
| RU | Russian Federation | * |
| RW | Rwanda | |
| SA | Saudi Arabia | * |
| SB | Solomon Islands | |
| SC | Seychelles | |
| SD | Sudan | |
| SE | Sweden | * |
| SG | Singapore | * |
| SH | St. Helena | |
| SI | Slovenia | * |
| SJ | Svalbard & Jan Mayen Is | |
| SK | Slovakia (Slovak Rep) | * |
| SL | Sierra Leone | |
| SM | San Marino | |
| SN | Senegal | |
| SO | Somalia | |
| SR | Suriname | |
| ST | St. Tome and Principe | |
| SU | Soviet Union (former) | * |
| SV | El Salvador | * |
| SY | Syria | |
| SZ | Swaziland | |
| TC | Turks & Caicos Islands | |
| TD | Chad | |
| TF | French Southern Terr. | |
| TG | Togo | |
| TH | Thailand | * |
| TJ | Tadjikistan | |
| TK | Tokelau | |
| TM | Turkmenistan | |
| TN | Tunisia | |
| TO | Tonga | |
| TP | East Timor | |
| TR | Turkey | * |
| TT | Trinidad & Tobago | * |
| TV | Tuvalu | |
| TW | Taiwan | * |
| TZ | Tanzania | |
| UA | Ukraine | * |
| UG | Uganda | |
| UK | United Kingdom | * |
| UM | US Minor outlying Isl. | |
| US | United States | * |
| UY | Uruguay | * |
| UZ | Uzbekistan | |
| VA | Vatican City State | |
| VC | St.Vincent & Grenadines | |
| VE | Venezuela | * |
| VG | Virgin Islands (British | |
| VI | Virgin Islands (US) | |
| VN | Vietnam | |
| VU | Vanuatu | |
| WF | Wallis & Futuna Islands | |
| WS | Western Samoa | |
| YE | Yemen | |
| YT | Mayotte | |
| YU | Yugoslavia | * |
| ZA | South Africa | * |
| ZM | Zambia | |
| ZR | Zaire | |
| ZW | Zimbabwe | * |
| com | US Commercial | * |
| edu | US Educational | * |
| gov | US Government | * |
| mil | US Military | * |
| net | Network | * |
| org | Non-Profit Organization | * |
| arpa | Old style Arpanet | * |
| army | Army | * |
* Active enough to show hits on uiuc or ucsd web sites.