In Irish writing that uses the dot-convention, the dot represents lenition. Vowel phonemes are not liable to lenition, so it doesn't make any sense to have a dotted i, any more than a dotted a, e, o, or u.
When you write Irish in an orthography where you put a dot on a consonant to show lenition, in the coded text there are two characters: the consonant, and COMBINING DOT ABOVE.
When you write Irish in an orthography where you put an accent on a vowel to show length, in the coded text there are two characters: the vowel, and COMBINING ACUTE.
The dot on the "i" in Roman fonts is NEVER, EVER, represented by Turkish � with COMBINING DOT ABOVE.
The acute acent on the "�" in Roman or Gaelic fonts is NEVER, EVER, represented by Turkish � with COMBINING ACUTE.
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Michael Everson * * Everson Typography * * http://www.evertype.com
