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Curly comma-like shapes for apostrophe and single-right-quote like characters, rather than straight-vertical or straight-slanted shapes. U+02BC Modifier Letter Apostrophe and most combining comma characters typically demonstrate the desired shape.
Local ogonek and glottal mark variant forms for some Haudenosaunee (Iroqouian) languages. Glottal mark and ogonek take the form of wedges that oppose each other in 180-degree rotation.
Ogonek wedge should be centered below the base letter. The top line of the glottal mark and bottom line of the ogonek need not be precisely aligned to the baselines; they are ideally tilted slightly further, so that the glottal mark wedge points even more upward and the ogonek wedge points even more downward.
Adjust Greek letter forms to a more Latin-like style for Latin-based writing systems that mix Latin and Greek characters, for example transcription systems or writing systems that adopt phonetic symbols. Narrower and more angular forms are preferred over circular and curled lines.
Examples include a narrower shape for θ theta characters (modeled on e.g. Times New Roman), or a serif form for λ lambda without the curled line.
Lower the middle of a vertically-centered character (e.g. mid dot) below the true center, on par with the horizontal line through A or e.
Adjust the placement of ◌̓ U+0313 Combining Comma Above to be more space-efficient and readable. Rather than appear above the tallest point of letters like k b ƛ (perhaps t č?), the combining mark should ideally be more lowered and centered, for example nested in the open space between the arms of letter k. (If moving slightly right, care should be taken to keep the placement distinct from that of U+0315 Combining Comma Above Right.)
Proportional lining figures for numeric characters 0123456789 are required. Old-style figures (etc) are not acceptable variations; number spacing should match letter spacing and surrounding text.
The ogonek hook should be horizontally centered below the base character, in contrast to standard forms like ą Ę where the hook may connect at the corner.
Give superscript letters (such as ⁿ) the same height and treatment as modifier letters (such as ʰ). They should be optimized for use in text rather than equations.
OpenType Layout implementation of variations:
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