Adobe PS: dieresis
Unicode: 00A8, 0308
Script: Greek
Dialytika
History and Examples of Use
In Greek, the dialytika indicates that the second of a pair of vowels is to be pronounced as a separate vowel rather than being treated as silent or as part of a diphthong.
Design
The form and position of the dialytika is similar to that of the Latin diaeresis, with obvious adaptation to the style of the particular Greek design, e.g. taller, more elliptical, slanted. In a font that supports both scripts, different forms for diaeresis and dialytika may be required for making composite diacritic glyphs.
There is a variant form of uppercase iota with dialytika (Ϊ) that is seen in display typography. In this variant, the two dots of the dialytika are lowered and placed one on either side of the Ι, usually a little higher than halfway up the stem. This looks best in well letterspaced all-caps.
Casing
When Greek text is set in all-caps or small-caps, tonos and other accent marks are conventionally removed. When the tonos/oxia falls on the first of two vowels that would otherwise be pronounced as a diphthong, this indicates that the two vowels are pronounced separately (if the tonos/oxia falls on the second vowel, this indicates that the diphthong is stressed). In this situation, when the tonos/oxia is removed from the first vowel in an all-caps setting, a dialytika needs to be inserted over the second vowel to indicate that it is pronounced separately, i.e. μάινα -> ΜΑΪΝΑ.
Casing of Greek accents for all-caps and small-caps can be handled contextually in OpenType fonts using the <calt> feature.