How many countries are there in the world and how are they defined? Six places that don't quite fit the definition

Many Pacific micro-nations have odd arrangements with bigger countries. Although self-governing, the Cook Islands, like Niue, has a "free association" with New Zealand, which looks after its defence and (to some extent) its foreign affairs, and provides citizenship and government services. Though not a UN member, it's belongs to several UN organisations. Other associated states in the Pacific are Palau, Micronesia and Marshall Islands, all linked to the USA. See cookislands.travel

SCOTLAND

Okay, Scotland isn't an independent country although, like England or Wales, is often called one in common usage. It does however have its own parliament (unlike England) and independent legal and education systems. It's treated like a nation when it comes to rugby and football, but not at the Olympics. And Scotland issues its own banknotes, though that doesn't mean much; three independent Pacific nations use the Australian dollar. As Brexit and independence issues rumble, watch this space. See visitscotland.com

SAHRAWI ARAB DEMOCRATIC REPUBLIC

A disputed territory widely known as Western Sahara runs down the coast of northwest Africa below Morocco. Most is occupied by Morocco and the rest by the Sahrawi Arab Democratic Republic which is a full member of the African Union and recognised by around 40 countries – though some countries' recognition is currently "suspended". This diplomatic knot has remained untangled since independence from Spain in 1975.

ANDORRA

Phew, nobody disputes this nation straddling the Pyrenees has been a country since 1278, but it's an odd one. Its dual heads of state are co-princes but neither is hereditary and neither elected by the Andorrans. The president of France (previously the French monarch) fills one role, the Spanish bishop of Urgel the other. If that doesn't confuse you enough, Andorra uses the euro but isn't part of the European Union. At 468 square kilometres, this is one of the world's smallest countries. See visitandorra.com

KOSOVO

Kosovo, formerly part of Yugoslavia and then Serbia, declared independence in 2008 to mixed reaction. It's recognised by about half of UN nations, including Australia – but not Serbia or some other European countries such as Spain and Greece. Fifteen governments, mostly in Africa and the Pacific, had initial enthusiasm but later withdrew recognition. It still isn't a United Nations member. Kosovo is the second-newest nation in the world after South Sudan (2011). See visitkosovo.rks-gov.net

ORDER OF MALTA

It sounds like something from a Dan Brown novel, but the Sovereign Military Hospitaller Order of Saint John of Jerusalem, of Rhodes and of Malta (to give it its official title) owns a few acres in Rome, issues its own currency and postage stamps, and gets diplomatic recognition from over 100 governments, though not Australia's. The Catholic religious order doesn't claim to be a state but frequently asserts its legal independence, which is recognised under international law. You can gaze at the outside of this "country" at the Palazzo Malta in Rome. See orderofmalta.int