Access All AlternatesThis 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.
Contextual AlternatesIn specified situations, replaces default glyphs with alternate forms which provide better joining behavior. Used in script typefaces which are designed to have some or all of their glyphs join.
Contextual LigaturesReplaces a sequence of glyphs with a single glyph which is preferred for typographic purposes. Unlike other ligature features, clig specifies the context in which the ligature is recommended. This capability is important in some script designs and for swash ligatures.
Contextual SwashThis feature replaces default character glyphs with corresponding swash glyphs in a specified context. Note that there may be more than one swash alternate for a given character.
Discretionary LigaturesReplaces 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.
DenominatorsReplaces selected figures which follow a slash with denominator figures.
FractionsReplaces figures separated by a slash with 'common' (diagonal) fractions.
Historical FormsSome letterforms were in common use in the past, but appear anachronistic today. The best-known example is the long form of s; others would include the old Fraktur k. Some fonts include the historical forms as alternates, so they can be used for a 'period' effect. This feature replaces the default (current) forms with the historical alternates. While some ligatures are also used for historical effect, this feature deals only with single characters.
Standard LigaturesReplaces 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.
Lining FiguresThis feature changes selected figures from oldstyle to the default lining form.
NumeratorsReplaces selected figures which precede a slash with numerator figures, and replaces the typographic slash with the fraction slash.
Oldstyle FiguresThis feature changes selected figures from the default lining style to oldstyle form.
OrdinalsReplaces 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.
OrnamentsThis is a dual-function feature, which uses two input methods to give the user access to ornament glyphs (e.g. fleurons, dingbats and border elements) in the font. One method replaces the bullet character with a selection from the full set of available ornaments; the other replaces specific "lower ASCII" characters with ornaments assigned to them. The first approach supports the general or browsing user; the second supports the power user.
Stylistic AlternatesMany 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.
Scientific InferiorsReplaces lining or oldstyle figures with inferior figures (smaller glyphs which sit lower than the standard baseline, primarily for chemical or mathematical notation). May also replace lowercase characters with alphabetic inferiors.
SuperscriptReplaces lining or oldstyle figures with superior figures (primarily for footnote indication), and replaces lowercase letters with superior letters (primarily for abbreviated French titles).
Tabular FiguresReplaces figure glyphs set on proportional widths with corresponding glyphs set on uniform (tabular) widths. Tabular widths will generally be the default, but this cannot be safely assumed. Of course this feature would not be present in monospaced designs.
Slashed Zero Some fonts contain both a default form of zero, and an alternative form which uses a diagonal slash through the counter. Especially in condensed designs, it can be difficult to distinguish between 0 and O (zero and capital O) in any situation where capitals and lining figures may be arbitrarily mixed. This feature allows the user to change from the default 0 to a slashed form.
