Access All Alternates

Tag: aalt

Function: This feature makes all variations of a selected character accessible. This serves several purposes: An application may not support the feature by which the desired glyph would normally be accessed; the user may need a glyph outside the context supported by the normal substitution, or the user may not know what feature produces the desired glyph. Since many-to-one substitutions are not covered, ligatures would not appear in this table unless they were variant forms of another ligature. A user inputs the P in Poetica, and is presented with a choice of the four standard capital forms, the eight swash capital forms, the initial capital form and the small capital form.

Denominators

Tag: dnom

Function: Replaces selected figures which follow a slash with denominator figures. In the string 11/17 selected by the user, the application turns the 17 into denominators when the user applies the fraction feature.

Fractions

Tag: frac

Function: Replaces figures separated by a slash with 'common' (diagonal) fractions. The user enters 3/4 in a recipe and gets the threequarters fraction.

Standard Ligatures

Tag: liga

Function: Replaces a sequence of glyphs with a single glyph which is preferred for typographic purposes. This feature covers the ligatures which the designer/manufacturer judges should be used in normal conditions. The glyph for ffl replaces the sequence of glyphs f f l.

Localized Forms

Tag: locl

Function: Many scripts used to write multiple languages over wide geographical areas have developed localized variant forms of specific letters, which are used by individual literary communities. For example, a number of letters in the Bulgarian and Serbian alphabets have forms distinct from their Russian counterparts and from each other. In some cases the localized form differs only subtly from the script 'norm', in others the forms are radically distinct. This feature enables localized forms of glyphs to be substituted for default forms. The user applies this feature to text to enable localized Bulgarian forms of Cyrillic letters; alternatively, the feature might enable localized Russian forms in a Bulgarian manufactured font in which the Bulgarian forms are the default characters.

Numerators

Tag: numr

Function: Replaces selected figures which precede a slash with numerator figures, and replaces the typographic slash with the fraction slash. In the string 11/17 selected by the user, the application turns the 11 into numerators, and the slash into a fraction slash when the user applies the fraction feature.

Ordinals

Tag: ordn

Function: Replaces default alphabetic glyphs with the corresponding ordinal forms for use after figures. One exception to the follows-a-figure rule is the numero character (U+2116), which is actually a ligature substitution, but is best accessed through this feature. The user applies this feature to turn 2.o into 2.o (abbreviation for secundo).

Superscript

Tag: sups

Function: Replaces lining or oldstyle figures with superior figures (primarily for footnote indication), and replaces lowercase letters with superior letters (primarily for abbreviated French titles). The application can use this feature to automatically access the superior figures (more legible than scaled figures) for footnotes, or the user can apply it to Mssr to get the classic form.

Swash

Tag: swsh

Function: This feature replaces default character glyphs with corresponding swash glyphs. Note that there may be more than one swash alternate for a given character. The user inputs the ampersand character when setting text with Poetica with this feature active, and is presented with a choice of the 63 ampersand forms in that face.

Small Capitals From Capitals

Tag: c2sc

Function: Small Capitals From Capitals

Small Capitals

Tag: smcp

Function: This feature turns lowercase characters into small capitals. This corresponds to the common SC font layout. It is generally used for display lines set in Large & small caps, such as titles. Forms related to small capitals, such as oldstyle figures, may be included. The user enters text as mixed capitals and lowercase, and gets Large & small cap text.

Stylistic Alternates

Tag: salt

Function: Many fonts contain alternate glyph designs for a purely esthetic effect; these don't always fit into a clear category like swash or historical. As in the case of swash glyphs, there may be more than one alternate form. This feature replaces the default forms with the stylistic alternates. The user applies this feature to Industria to get the alternate form of g.

Subscript

Tag: subs

Function: The "subs" feature may replace a default glyph with a subscript glyph, or it may combine a glyph substitution with positioning adjustments for proper placement. Recommended implementation: First, a single or contextual substitution lookup implements the subscript glyph (GSUB lookup type 1). Then, if the glyph needs repositioning, an application may apply a single adjustment, pair adjustment, or contextual adjustment positioning lookup to modify its position.

Discretionary Ligatures

Tag: dlig

Function: Replaces a sequence of glyphs with a single glyph which is preferred for typographic purposes. This feature covers those ligatures which may be used for special effect, at the user's preference. The glyph for ct replaces the sequence of glyphs c t, or U+322E (Kanji ligature for "Friday") replaces the sequence U+91D1 U+66DC U+65E5.

Sylistic Set 1

Tag: ss01

Function: In addition to, or instead of, stylistic alternatives of individual glyphs (see 'salt' feature), some fonts may contain sets of stylistic variant glyphs corresponding to portions of the character set, e.g. multiple variants for lowercase letters in a Latin font. Glyphs in stylistic sets may be designed to harmonise visually, interract in particular ways, or otherwise work together. Examples of fonts including stylistic sets are Zapfino Linotype and Adobe's Poetica. Individual features numbered sequentially with the tag name convention 'ss01' 'ss02' 'ss03' . 'ss20' provide a mechanism for glyphs in these sets to be associated via GSUB lookup indexes to default forms and to each other, and for users to select from available stylistic sets.

Sylistic Set 2

Tag: ss02

Function: In addition to, or instead of, stylistic alternatives of individual glyphs (see 'salt' feature), some fonts may contain sets of stylistic variant glyphs corresponding to portions of the character set, e.g. multiple variants for lowercase letters in a Latin font. Glyphs in stylistic sets may be designed to harmonise visually, interract in particular ways, or otherwise work together. Examples of fonts including stylistic sets are Zapfino Linotype and Adobe's Poetica. Individual features numbered sequentially with the tag name convention 'ss01' 'ss02' 'ss03' . 'ss20' provide a mechanism for glyphs in these sets to be associated via GSUB lookup indexes to default forms and to each other, and for users to select from available stylistic sets.

Sylistic Set 3

Tag: ss03

Function: In addition to, or instead of, stylistic alternatives of individual glyphs (see 'salt' feature), some fonts may contain sets of stylistic variant glyphs corresponding to portions of the character set, e.g. multiple variants for lowercase letters in a Latin font. Glyphs in stylistic sets may be designed to harmonise visually, interract in particular ways, or otherwise work together. Examples of fonts including stylistic sets are Zapfino Linotype and Adobe's Poetica. Individual features numbered sequentially with the tag name convention 'ss01' 'ss02' 'ss03' . 'ss20' provide a mechanism for glyphs in these sets to be associated via GSUB lookup indexes to default forms and to each other, and for users to select from available stylistic sets.

Sylistic Set 4

Tag: ss04

Function: In addition to, or instead of, stylistic alternatives of individual glyphs (see 'salt' feature), some fonts may contain sets of stylistic variant glyphs corresponding to portions of the character set, e.g. multiple variants for lowercase letters in a Latin font. Glyphs in stylistic sets may be designed to harmonise visually, interract in particular ways, or otherwise work together. Examples of fonts including stylistic sets are Zapfino Linotype and Adobe's Poetica. Individual features numbered sequentially with the tag name convention 'ss01' 'ss02' 'ss03' . 'ss20' provide a mechanism for glyphs in these sets to be associated via GSUB lookup indexes to default forms and to each other, and for users to select from available stylistic sets.

Sylistic Set 5

Tag: ss05

Function: In addition to, or instead of, stylistic alternatives of individual glyphs (see 'salt' feature), some fonts may contain sets of stylistic variant glyphs corresponding to portions of the character set, e.g. multiple variants for lowercase letters in a Latin font. Glyphs in stylistic sets may be designed to harmonise visually, interract in particular ways, or otherwise work together. Examples of fonts including stylistic sets are Zapfino Linotype and Adobe's Poetica. Individual features numbered sequentially with the tag name convention 'ss01' 'ss02' 'ss03' . 'ss20' provide a mechanism for glyphs in these sets to be associated via GSUB lookup indexes to default forms and to each other, and for users to select from available stylistic sets.

Glyph Composition/Decomposition

Tag: ccmp

Function: To minimize the number of glyph alternates, it is sometimes desired to decompose a character into two glyphs. Additionally, it may be preferable to compose two characters into a single glyph for better glyph processing. This feature permits such composition/decompostion. The feature should be processed as the first feature processed, and should be processed only when it is called. In Syriac, the character 0x0732 is a combining mark that has a dot above AND a dot below the base character. To avoid multiple glyph variants to fit all base glyphs, the character is decomposed into two glyphs...a dot above and a dot below. These two glyphs can then be correctly placed using GPOS. In Arabic it might be preferred to combine the shadda with fatha (0x0651, 0x064E) into a ligature before processing shapes. This allows the font vendor to do special handling of the mark combination when doing further processing without requiring larger contextual rules.

Tag: lowercase

Function:

Tag: uppercase

Function: