| | AD | Andorra |
| | AE | United Arab Emirates |
| | AF | Afghanistan |
| | AG | Antigua and Barbuda |
| | AI | Anguilla |
| | AL | Albania |
| | AM | Armenia |
| | AN | Netherlands Antilles |
| | AO | Angola |
| | AQ | Antarctica |
| | AR | Argentina |
| | AS | American Samoa |
| | AT | Austria |
| | AU | Australia |
| | AW | Aruba |
| | AZ | Azerbaijan |
| | BA | Bosnia and 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 |
| | CG | Congo |
| | CH | Switzerland |
| | CI | Cote D'Ivoire (Ivory Coast) |
| | CK | Cook Islands |
| | CL | Chile |
| | CM | Cameroon |
| | CN | China |
| | CO | Colombia |
| | CR | Costa Rica |
| | CS | Czechoslovakia (former) |
| | 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 Islands (Malvinas) |
| | FM | Micronesia |
| | FO | Faroe Islands |
| | FR | France |
| | FX | France, Metropolitan |
| | GA | Gabon |
| | GB | Great Britain (UK) |
| | GD | Grenada |
| | GE | Georgia |
| | GF | French Guiana |
| | GH | Ghana |
| | GI | Gibraltar |
| | GL | Greenland |
| | GM | Gambia |
| | GN | Guinea |
| | GP | Guadeloupe |
| | GQ | Equatorial Guinea |
| | GR | Greece |
| | GS | S. Georgia and S. Sandwich Isls. |
| | GT | Guatemala |
| | GU | Guam |
| | GW | Guinea-Bissau |
| | GY | Guyana |
| | HK | Hong Kong |
| | HM | Heard and McDonald Islands |
| | HN | Honduras |
| | HR | Croatia (Hrvatska) |
| | HT | Haiti |
| | HU | Hungary |
| | ID | Indonesia |
| | IE | Ireland |
| | IL | Israel |
| | IN | India |
| | IO | British Indian Ocean Territory |
| | IQ | Iraq |
| | IR | Iran |
| | IS | Iceland |
| | IT | Italy |
| | JM | Jamaica |
| | JO | Jordan |
| | JP | Japan |
| | KE | Kenya |
| | KG | Kyrgyzstan |
| | KH | Cambodia |
| | KI | Kiribati |
| | KM | Comoros |
| | KN | Saint Kitts and Nevis |
| | KP | Korea (North) |
| | KR | Korea (South) |
| | 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 | Moldova |
| | MG | Madagascar |
| | MH | Marshall Islands |
| | MK | Macedonia |
| | ML | Mali |
| | MM | Myanmar |
| | MN | Mongolia |
| | MO | Macau |
| | MP | Northern Mariana Islands |
| | MQ | Martinique |
| | MR | Mauritania |
| | MS | Montserrat |
| | MT | Malta |
| | MU | Mauritius |
| | MV | Maldives |
| | MW | Malawi |
| | MX | Mexico |
| | MY | Malaysia |
| | MZ | Mozambique |
| | NA | Namibia |
| | NC | New Caledonia |
| | NE | Niger |
| | NF | Norfolk Island |
| | NG | Nigeria |
| | NI | Nicaragua |
| | NL | Netherlands |
| | NO | Norway |
| | NP | Nepal |
| | NR | Nauru |
| | NT | Neutral Zone |
| | NU | Niue |
| | NZ | New Zealand (Aotearoa) |
| | OM | Oman |
| | PA | Panama |
| | PE | Peru |
| | PF | French Polynesia |
| | PG | Papua New Guinea |
| | PH | Philippines |
| | PK | Pakistan |
| | PL | Poland |
| | PM | St. Pierre and Miquelon |
| | PN | Pitcairn |
| | PR | Puerto Rico |
| | PT | Portugal |
| | PW | Palau |
| | PY | Paraguay |
| | QA | Qatar |
| | RE | Reunion |
| | 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 and Jan Mayen Islands |
| | SK | Slovak Republic |
| | SL | Sierra Leone |
| | SM | San Marino |
| | SN | Senegal |
| | SO | Somalia |
| | SR | Suriname |
| | ST | Sao Tome and Principe |
| | SU | USSR (former) |
| | SV | El Salvador |
| | SY | Syria |
| | SZ | Swaziland |
| | TC | Turks and Caicos Islands |
| | TD | Chad |
| | TF | French Southern Territories |
| | TG | Togo |
| | TH | Thailand |
| | TJ | Tajikistan |
| | 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 | US Minor Outlying Islands |
| | US | United States |
| | UY | Uruguay |
| | UZ | Uzbekistan |
| | VA | Vatican City State (Holy See) |
| | VC | Saint Vincent and the Grenadines |
| | VE | Venezuela |
| | VG | Virgin Islands (British) |
| | VI | Virgin Islands (U.S.) |
| | VN | Viet Nam |
| | VU | Vanuatu |
| | WF | Wallis and Futuna Islands |
| | WS | 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 |
| | INT | International |
| | MIL | US Military |
| | NET | Network |
| | ORG | Non-Profit Organization |
| | ARPA | Old style Arpanet |
| | NATO | Nato field |