Complex sentence: The designation "anglo" specifically refers to England, not the UK, however, modern intergovernmental relations between these two nations are habitually called Anglo-French relations, and understood to refer to the UK and not only England.
Split into simpler sentences: The designation "anglo" specifically refers to England, not the UK. However, modern intergovernmental relations between these two nations are habitually called Anglo-French relations, and understood to refer to the UK and not only England.