This first one is for countries of the world
| Afghanistan | #AFG |
| Åland Islands | #ALA |
| Albania | #ALB |
| Algeria | #DZA |
| American Samoa | #ASM |
| Andorra | #AND |
| Angola | #AGO |
| Anguilla | #AIA |
| Antigua and Barbuda | #ATG |
| Argentina | #ARG |
| Armenia | #ARM |
| Aruba | #ABW |
| Australia | #AUS |
| Austria | #AUT |
| Azerbaijan | #AZE |
| Bahamas | #BHS |
| Bahrain | #BHR |
| Bangladesh | #BGD |
| Barbados | #BRB |
| Belarus | #BLR |
| Belgium | #BEL |
| Belize | #BLZ |
| Benin | #BEN |
| Bermuda | #BMU |
| Bhutan | #BTN |
| Bolivia | #BOL |
| Bosnia and Herzegovina | #BIH |
| Botswana | #BWA |
| Brazil | #BRA |
| British Virgin Islands | #VGB |
| Brunei | #BRN |
| Bulgaria | #BGR |
| Burkina Faso | #BFA |
| Burundi | #BDI |
| Cambodia | #KHM |
| Cameroon | #CMR |
| Canada | #CAN |
| Cape Verde | #CPV |
| Cayman Islands | #CYM |
| Central African Republic | #CAF |
| Chad | #TCD |
| Chile | #CHL |
| China | #CHN |
| China, Hong Kong | #HKG |
| China, Macao | #MAC |
| Colombia | #COL |
| Comoros | #COM |
| Congo | #COG |
| Cook Islands | #COK |
| Costa Rica | #CRI |
| Côte d’Ivoire | #CIV |
| Croatia | #HRV |
| Cuba | #CUB |
| Cyprus | #CYP |
| Czech Republic | #CZE |
| Democratic Republic of the Congo | #COD |
| Denmark | #DNK |
| Djibouti | #DJI |
| Dominica | #DMA |
| Dominican Republic | #DOM |
| Ecuador | #ECU |
| Egypt | #EGY |
| El Salvador | #SLV |
| Equatorial Guinea | #GNQ |
| Eritrea | #ERI |
| Estonia | #EST |
| Ethiopia | #ETH |
| Faeroe Islands | #FRO |
| Falkland Islands (Malvinas) | #FLK |
| Fiji | #FJI |
| Finland | #FIN |
| France | #FRA |
| French Guiana | #GUF |
| French Polynesia | #PYF |
| Gabon | #GAB |
| Gambia | #GMB |
| Georgia | #GEO |
| Germany | #DEU |
| Ghana | #GHA |
| Gibraltar | #GIB |
| Greece | #GRC |
| Greenland | #GRL |
| Grenada | #GRD |
| Guadeloupe | #GLP |
| Guam | #GUM |
| Guatemala | #GTM |
| Guernsey | #GGY |
| Guinea | #GIN |
| Guinea-Bissau | #GNB |
| Guyana | #GUY |
| Haiti | #HTI |
| Honduras | #HND |
| Hungary | #HUN |
| Iceland | #ISL |
| India | #IND |
| Indonesia | #IDN |
| Iran | #IRN |
| Iraq | #IRQ |
| Ireland | #IRL |
| Isle of Man | #IMN |
| Israel | #ISR |
| Italy | #ITA |
| Jamaica | #JAM |
| Japan | #JPN |
| Jersey | #JEY |
| Jordan | #JOR |
| Kazakhstan | #KAZ |
| Kenya | #KEN |
| Kiribati | #KIR |
| Kosovo | #RKS |
| Kuwait | #KWT |
| Kyrgyzstan | #KGZ |
| Lao People’s Democratic Republic | #LAO |
| Latvia | #LVA |
| Lebanon | #LBN |
| Lesotho | #LSO |
| Liberia | #LBR |
| Libya | #LBY |
| Liechtenstein | #LIE |
| Lithuania | #LTU |
| Luxembourg | #LUX |
| Macedonia | #MKD |
| Madagascar | #MDG |
| Malawi | #MWI |
| Malaysia | #MYS |
| Maldives | #MDV |
| Mali | #MLI |
| Malta | #MLT |
| Marshall Islands | #MHL |
| Martinique | #MTQ |
| Mauritania | #MRT |
| Mauritius | #MUS |
| Mayotte | #MYT |
| Mexico | #MEX |
| Micronesia | #FSM |
| Monaco | #MCO |
| Mongolia | #MNG |
| Montenegro | #MNE |
| Montserrat | #MSR |
| Morocco | #MAR |
| Mozambique | #MOZ |
| Myanmar | #MMR |
| Namibia | #NAM |
| Nauru | #NRU |
| Nepal | #NPL |
| Netherlands | #NLD |
| Netherlands Antilles | #ANT |
| New Caledonia | #NCL |
| New Zealand | #NZL |
| Nicaragua | #NIC |
| Niger | #NER |
| Nigeria | #NGA |
| Niue | #NIU |
| Norfolk Island | #NFK |
| North Korea | #PRK |
| Northern Mariana Islands | #MNP |
| Norway | #NOR |
| Occupied Palestinian Territory | #PSE |
| Oman | #OMN |
| Pakistan | #PAK |
| Palau | #PLW |
| Panama | #PAN |
| Papua New Guinea | #PNG |
| Paraguay | #PRY |
| Peru | #PER |
| Philippines | #PHL |
| Pitcairn | #PCN |
| Poland | #POL |
| Portugal | #PRT |
| Puerto Rico | #PRI |
| Qatar | #QAT |
| Republic of Korea | #KOR |
| Republic of Moldova | #MDA |
| Réunion | #REU |
| Romania | #ROU |
| Russian Federation | #RUS |
| Rwanda | #RWA |
| Saint Helena | #SHN |
| Saint Kitts and Nevis | #KNA |
| Saint Lucia | #LCA |
| Saint Pierre and Miquelon | #SPM |
| Saint Vincent & the Grenadines | #VCT |
| Saint-Barthélemy | #BLM |
| Saint-Martin (French part) | #MAF |
| Samoa | #WSM |
| San Marino | #SMR |
| Sao Tome and Principe | #STP |
| Saudi Arabia | #SAU |
| Senegal | #SEN |
| Serbia | #SRB |
| Seychelles | #SYC |
| Sierra Leone | #SLE |
| Singapore | #SGP |
| Slovakia | #SVK |
| Slovenia | #SVN |
| Solomon Islands | #SLB |
| Somalia | #SOM |
| South Africa | #ZAF |
| Spain | #ESP |
| Sri Lanka | #LKA |
| Sudan | #SDN |
| Suriname | #SUR |
| Swaziland | #SWZ |
| Sweden | #SWE |
| Switzerland | #CHE |
| Syrian Arab Republic | #SYR |
| Taiwan | #TWN |
| Tajikistan | #TJK |
| Tanzania | #TZA |
| Thailand | #THA |
| Timor-Leste | #TLS |
| Togo | #TGO |
| Tokelau | #TKL |
| Tonga | #TON |
| Trinidad and Tobago | #TTO |
| Tunisia | #TUN |
| Turkey | #TUR |
| Turkmenistan | #TKM |
| Turks and Caicos Islands | #TCA |
| Tuvalu | #TUV |
| Uganda | #UGA |
| Ukraine | #UKR |
| United Arab Emirates | #ARE |
| United Kingdom | #GBR |
| United States of America | #USA |
| United States Virgin Islands | #VIR |
| Uruguay | #URY |
| Uzbekistan | #UZB |
| Vanuatu | #VUT |
| Vatican | #VAT |
| Venezuela | #VEN |
| Viet Nam | #VNM |
| Wallis and Futuna Islands | #WLF |
| Western Sahara | #ESH |
| Yemen | #YEM |
| Zambia | #ZMB |
| Zimbabwe | #ZWE |
The second is a best guess based on official US Post Office Abbreviations. Many tweeters also use a states full name spelled out.
| State/Possession | Abbreviation | |
|---|---|---|
| ALABAMA | AL | |
| ALASKA | AK | |
| AMERICAN SAMOA | AS | |
| ARIZONA | AZ | |
| ARKANSAS | AR | |
| CALIFORNIA | CA | |
| COLORADO | CO | |
| CONNECTICUT | CT | |
| DELAWARE | DE | |
| DISTRICT OF COLUMBIA | DC | |
| FEDERATED STATES OF MICRONESIA | FM | |
| FLORIDA | FL | |
| GEORGIA | GA | |
| GUAM | GU | |
| HAWAII | HI | |
| IDAHO | ID | |
| ILLINOIS | IL | |
| INDIANA | IN | |
| IOWA | IA | |
| KANSAS | KS | |
| KENTUCKY | KY | |
| LOUISIANA | LA | |
| MAINE | ME | |
| MARSHALL ISLANDS | MH | |
| MARYLAND | MD | |
| MASSACHUSETTS | MA | |
| MICHIGAN | MI | |
| MINNESOTA | MN | |
| MISSISSIPPI | MS | |
| MISSOURI | MO | |
| MONTANA | MT | |
| NEBRASKA | NE | |
| NEVADA | NV | |
| NEW HAMPSHIRE | NH | |
| NEW JERSEY | NJ | |
| NEW MEXICO | NM | |
| NEW YORK | NY | |
| NORTH CAROLINA | NC | |
| NORTH DAKOTA | ND | |
| NORTHERN MARIANA ISLANDS | MP | |
| OHIO | OH | |
| OKLAHOMA | OK | |
| OREGON | OR | |
| PALAU | PW | |
| PENNSYLVANIA | PA | |
| PUERTO RICO | PR | |
| RHODE ISLAND | RI | |
| SOUTH CAROLINA | SC | |
| SOUTH DAKOTA | SD | |
| TENNESSEE | TN | |
| TEXAS | TX | |
| UTAH | UT | |
| VERMONT | VT | |
| VIRGIN ISLANDS | VI | |
| VIRGINIA | VA | |
| WASHINGTON | WA | |
| WEST VIRGINIA | WV | |
| WISCONSIN | WI | |
| WYOMING | WY | |
