II. CLASSIFICATIONS (from left to right in the political spectrum)
   
 Communism: Communist parties primarily adhere to Marxism developed by Karl Marx and Friedrich Engels in the 19th century. Their aim is the free and classless society based on common ownership of the means of production. This parties intend to overthrow the present capitalist system through revolutionary action of the working class. They often originated after the Russian Revolution of 1917 from leftist factions of socialist or social democratic parties.

- Marxism-Leninism: Marxist-Leninist (Leninist) parties prefer a non-pluralist orthodox form of communism developed by Vladimir Ilyich Lenin (leadership of a vanguard party, dictatorship of the proletariat, centralism).

- Trotskyism: Trotskyist parties favour a non-pluralist form of communism established by Leon Trotsky (leadership of a vanguard party, dictatorship of the proletariat, proletarian internationalism, permanent revolution).

 Socialism: Socialist parties oppose the present capitalist system and intend to establish a social and economic system characterised by social ownership of the means of production and co-operative management of the economy (state-owned enterprises, employee-owned cooperatives, common ownership). They advocate a society characterised by equal access to resources for all individuals. In general, they emphasise values as equality, solidarity and social justice.

- Democratic socialism: Democratic socialist parties advocate a strong welfare state with a large public sector. They resist the capitalist globalisation and propose a reorganisation of the present socio-economic order through more public ownership, workers' control of the labour process and redistributive tax policies.

- Eco-socialism: Eco-socialist parties combine socialist, green and anti-globalisation policies.

 Green politics: Most of the green and alternative parties were founded in the late 1970s as part of the new social movements that came up in the mid-1960s (in particular the ecology, peace, women's and anti-nuclear movements). This parties aim to create an ecologically sustainable society rooted in environmentalism, feminism, nonviolence, social justice and LGBT, civil and human rights.

 Social democracy: Social democratic parties are centre-left parties rooted in the socialist labour movement of the 19th century. They advocate a democratic welfare state and a mixed economy that contains privately-owned and state-owned enterprises. This parties adhere to values as freedom, equality, solidarity and social justice. Since the 1990s, most of them incorporated economically liberal topics as limited social welfare, privatisations, deregulations and lower company taxes (Third Way).

 Regionalism: Regionalist (autonomist) parties focus on the interests of a particular region within a state. They generally intend to secure or to increase the region's influence. Their aim is a decentralisation of governance, self-determination and regional autonomy.

- Separatism: Separatist parties usually advocate a full political secession of a particular region with its ethnical, linguistical or cultural identity and the formation of a new state.

 Minority interests: Parties of minorities intend to secure or to increase the rights of an ethnical or linguistical minority.

 Centrism: Centrist parties are usually moderate traditionalist parties which take a centrist position on the socio-economic left-right scale.

 Liberalism: Liberal parties are middle-class parties based on the tradition of political liberalism, a movement of the 18th century. The doctrine of liberalism considers personal freedom to be the most important goal. In particular it favours free markets, free trade, limited governments, low taxes and private property (economic liberalism) as well as equality for all citizens under the law, civil rights, secularism and freedom of speech, press and religion.

- Conservative liberalism: Conservative liberal parties combine liberal policies with more traditional stances on social and ethical issues (in some countries this form of right-wing liberalism is traditionally known as national liberalism).

- Social liberalism: Social liberal parties stress civil rights and favour a social market economy.

 Christian democracy: The Christian social doctrine (basic principle: human dignity) is the main inspiration of Christian democratic parties. This cross-class parties advocate Christian ethical and moderate social conservative stances. They are very supportive of family values and adhere to principles as freedom, solidarity and subsidiarity. This parties oppose any form of secularism. Usually they advocate a social market economy.

 Conservatism: Originally inspired by natural law and formed by the upper-class, conservative parties today are usually middle-class organisations that seek to preserve established traditions and the current status quo of a society. They normally advocate traditional values as authority, nation, religion, family, stability and continuity. Over the time they incorporated some liberal values, especially on economic issues (free market policies).

- Liberal conservatism: Liberal conservative parties combine conservative policies with more liberal stances on social and ethical issues.

- Social conservatism: Social conservative parties focus on the preservation of traditional social, ethical and religious values. They usually advocate a social market economy.

- National conservatism: National conservative parties combine conservative policies with national stances. They oppose a further European integration and prefer the preservation of the nation-state with its cultural identity. This parties usually favour social stability and traditional social, ethical and religious values.

 Right-wing populism: Right-wing populist parties are protest parties that appeal to the "common man". They appeared first in the early 1970s. This parties combine national stances with an anti-elitist rhetoric and a radical critique of the political institutions. They usually prefer strict law-and-order and anti-immigration polices.

 Nationalism: Nationalist parties believe that the nation with its collective ethnic, linguistic and cultural identity, its natural order and its sovereignty is of primary importance. This involves a strong identification with the nation state and its symbols. It usually also includes negative views of other nations or other ethnic, linguistic and cultural groups.

- Far-right politics: Far-right parties are ultra-nationalist parties that adhere to a pure form of the nation defined by ethnicity. They challenge the equality of all humans and believe that a nation state requires a collective identity and a strong leadership. This parties tend to authoritarianism, xenophobia and corporatism. They usually oppose the present democratic systems and their values.

 Others: Agrarianism, Animal welfare, Anti-clericalism, Anti-corruption politics, Anti-globalisation, Basic income, Christian left, Christian right, Copyright reform, Direct democracy, Environmentalism, Euroscepticism, Evangelicalism, Feminism, Gaullism, Islamism, Kemalism, Loyalism, Libertarianism, Monarchism, Multiculturalism, Pensioners' interests, Statism, Transparency, Unionism.
  

III. ABBREVIATIONS
  
AMS: Additional member system; FPTP: First-past-the-post; MMP: Mixed-member proportional representation; PR: Party-list proportional representation; STV: Single transferable vote; TRS: Two-round system; MEP: Member of the European Parliament; S.: Seats; ... : Not specified.