Order of the British Empire
Only the two highest ranks are knighthoods, and allow the holder to call themselves 'Sir' (male) or 'Dame' (female). If the person is not a citizen of a country where the King is Head of State, the award is called honorary, and the holder cannot use the title before their name. For example Terry Wogan became a British citizen and was therefore called Sir Terry Wogan, but Bob Geldof is still an Irish citizen, and is therefore not "Sir Bob". He can, however, style himself "Bob Geldof KBE".