Diacritic
A different principle is illustrated by the circumflex î. This usually shows the loss of letter: e.g. maistre (Middle French) > maître (modern French). Thus its function is historical. Also, less often, the circumflex is used to distinguish between homophones. These are words spelt the same, but with different meanings. Example: sur = on, but sûr = safe. In those cases the pronunciation of the two words may be different.