Macron

A macron is a punctuation mark ¯ placed over a vowel. It is usually used in pronunciation guides as an indication that the vowel has a long sound. In Hawaiian it is used to indicate stress. In Latvian it is used to indicate a long A sound. The macron is also used in the Hepburn transcription of Japanese to indicate a long vowel, as in kōtsū 'traffic' as opposed to kotsu 'bone' or 'knack (fig.)'. In Pinyin it is used to indicate one of four Mandarin tones. It is often used in modern Latin dictionaries to mark vowel length.

Vowel length in New Zealand Māori is phonemic, i.e. vowels are either pronounced short or long. Early writing in Māori did not distinguish vowel length. Some have advocated that the double vowel orthography be used to distinguish vowel length. However, the Māori Language Commission (Te Taura Whiri) advocate a macron be used to designate a long vowel. The use of the macron is now wide spread in modern Māori writings.

The HTML/Unicode numbers for macron letters are:

Upper Case		Lower Case
Letter	HTML	Letter	HTML
Ā	Ā	ā	ā
Ē	Ē	ē	ē
Ī	Ī	ī	ī
Ō	Ō	ō	ō
Ū	Ū	ū	ū
Ǖ	Ǖ	ǖ	ǖ

The final row is the letter U/u with macron and diaeresis.