Case-Sensitive Forms

Tag: case

Function: Shifts various punctuation marks up to a position that works better with all-capital sequences or sets of lining figures; also changes oldstyle figures to lining figures. By default, glyphs in a text face are designed to work with lowercase characters. Some characters should be shifted vertically to fit the higher visual center of all-capital or lining text. Also, lining figures are the same height (or close to it) as capitals, and fit much better with all-capital text. The user selects a block of text and applies this feature. The dashes, bracketing characters, guillemet quotes and the like shift up to match the capitals, and oldstyle figures change to lining figures.

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.

Lining Figures

Tag: lnum

Function: This feature changes selected figures from oldstyle to the default lining form. The user invokes this feature in order to get lining figures, which fit better with all-capital text. Various characters designed to be used with figures may also be covered by this feature. In cases where lining figures are the default form, this feature would undo previous substitutions.

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.

Old Style Figures

Tag: onum

Function: This feature changes selected figures from the default lining style to oldstyle form. The user invokes this feature to get oldstyle figures, which fit better into the flow of normal upper- and lowercase text. Various characters designed to be used with figures may also have oldstyle versions.

Proportional Figures

Tag: pnum

Function: Replaces figure glyphs set on uniform (tabular) widths with corresponding glyphs set on glyph-specific (proportional) 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. The user may apply this feature to get even spacing for lining figures used as dates in an all-cap headline.

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.

Tabular Figures

Tag: tnum

Function: Replaces 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. The user may apply this feature to get oldstyle figures to align vertically in a column.

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.

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.

Slashed Zero

Tag: zero

Function: 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. When setting labels, the user applies this feature to get the slashed 0.

Required Ligatures

Tag: rlig

Function: Replaces a sequence of glyphs with a single glyph which is preferred for typographic purposes. This feature covers those ligatures, which the script determines as required to be used in normal conditions. This feature is important for some scripts to insure correct glyph formation. The Arabic character lam followed by alef will always form a ligated lamalef form. This ligated form is a requirement of the script's shaping. The same happens with the Syriac script.

Tag: lowercase

Function:

Tag: uppercase

Function: