Names of persons or places (Papadopoulos Konstantinos, Thessaloniki, Cyprus, Lower Saxony, Black Sea but Aegean Sea, Mediterranean Sea, Nile River, etc.), the federations of states (the Federal Republic of Germany, the French Republic, the United Kingdom of Great Britain and Northern Ireland), titles of honor and office (Prime Minister, Archbishop, Speaker of the Parliament) , Officer, Baron, King, etc.), the names of state institutional bodies of governmental and legislative authority as well as international organizations (Ministry of National Education and Religious Affairs, Areios Pagos, Parliament, Congress, Senate, Areios Pagos, Council of State, European Union , Organization for Economic Cooperation and Development, European Parliament, European Economic and Social Committee, European Committee of the Regions, etc.), names of institutions, university schools, companies, associations (Aniaton Foundation, National and Kapodistrian University of Athens, National Technical University of Athens, Alpha Exchange, etc.) .), the names of months, days of the week, holidays, historical events (June, Tuesday, World War II, Easter, Christmas, Ramadan, Greek Revolution).
We write: Greek (but Greek politician, Greek poetry, Greek, Greek), East (but Eastern), English (but English engineer, English, English language, English), Christ (but Christian, Christianity), Christmas (but Christmas), God (but divine), Sunday (but Sunday morning), Easter (but Easter egg), Russia (but Russian marble, Russian language).
ATTENTION: When referring to a specific geographical area (or educational institution, or government/legal entity, or rule/regulation, or title/office, etc.) then we capitalize the first letter of all words. Conversely, when we do not specify the geographic area (or the educational institution, or the governmental/legal entity, or the rule/regulation, or the title/office) and our reference is general or vague then we lowercase the entire word .
Examples: the university (but Aristotle University), the president (but the Speaker of Parliament), the sun (the Sun of our solar system), earth (but planet Earth), the museum (but the British Museum), Roman (but Holy Roman Empire of the German Nation), Byzantine (but Byzantine Empire), the treaty (but the Treaty of Lausanne), the budget committee (but the Commission of the European Communities), the council (but the Council of the European Union), catholic (but the Roman Catholic Church), treaty (but the Treaty of Lausanne), the budget committee (but the Commission of the European Communities), the council (but the Council of the European Union), northern Greece (when we do not specify a geographical area) but Northern Greece (when we refer to the whole of the parts of northern Greece that are Macedonia and Thrace), the press (when we specifically refer to the media) but we write the mathematical formula (since we do not make a specific reference).
But when only one word is part of the name we are referring to, then we capitalize only the first letter of the main name. However, when all the words are part of the name we are referring to, then we capitalize the first letter of all the words
Examples: Lower Saxony, but Aegean Sea, Nile River, Mediterranean Sea but Black Sea (since the words "Black Sea" are the main name), etc.