OpenType font format
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.
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.
Function:: Replaces figures separated by a slash with 'common' (diagonal) fractions. The user enters 3/4 in a recipe and gets the threequarters fraction.
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.
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.
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).
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.
Function:: Replaces 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. The application can use this feature to automatically access the inferior figures (more legible than scaled figures).
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.
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.
Function:: Small Capitals From Capitals
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.
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.
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.
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.
Function:: Adjusts amount of space between glyphs, generally to provide optically consistent spacing between glyphs. Although a well-designed typeface has consistent inter-glyph spacing overall, some glyph combinations require adjustment for improved legibility. Besides standard adjustment in the horizontal direction, this feature can supply size-dependent kerning data via device tables, "cross-stream" kerning in the Y text direction, and adjustment of glyph placement independent of the advance adjustment. Note that this feature may apply to runs of more than two glyphs, and would not be used in monospaced fonts. Also note that this feature does not apply to text set vertically. The o is shifted closer to the T in the combination "To."
Function:: This feature stores two kinds of information about the optical size of the font: design size (the point size for which the font is optimized) and size range (the range of point sizes which the font can serve well), as well as other information which helps applications use the size range. The design size is useful for determining proper tracking behavior. The size range is useful in families which have fonts covering several ranges. Additional values serve to identify the set of fonts which share related size ranges, and to identify their shared name. Note that sizes refer to nominal final output size, and are independent of viewing magnification or resolution. Required implementation: The Feature table of this GPOS feature contains no lookups; its Feature Parameters field records an offset from the beginning of the Feature table to an array of five 16-bit unsigned integer values. The size feature must be implemented in all fonts in any family which uses the feature. In this usage, a family is a set of fonts which share a Preferred Family name (name ID 16), or Font Family name (name ID 1) if the Preferred Family name is absent.<BR> The first value represents the design size in 720/inch units (decipoints). The design size entry must be non-zero. When there is a design size but no recommended size range, the rest of the array will consist of zeros. The second value has no independent meaning, but serves as an identifier that associates fonts in a subfamily. All fonts which share a Preferred or Font Family name and which differ only by size range shall have the same subfamily value, and no fonts which differ in weight or style shall have the same subfamily value. If this value is zero, the remaining fields in the array will be ignored. The third value enables applications to use a single name for the subfamily identified by the second value. If the preceding value is non-zero, this value must be set in the range 256 - 32767 (inclusive). It records the value of a field in the name table, which must contain English-language strings encoded in Windows Unicode and Macintosh Roman, and may contain additional strings localized to other scripts and languages. Each of these strings is the name an application should use, in combination with the family name, to represent the subfamily in a menu. Applications will choose the appropriate version based on their selection criteria. The fourth and fifth values represent the small end of the recommended usage range (exclusive) and the large end of the recommended usage range (inclusive), stored in 720/inch units (decipoints). Ranges must not overlap, and should generally be contiguous. The size information in Bell Centennial is [60 0 0 0 0]. This tells an application that the fontâs design size is six points, so larger sizes may need proportionate reduction in default inter-glyph spacing. The size information in Minion Pro Semibold Condensed Subhead is [180 3 257 139 240]. These values tell an application that: The font's design size is 18 points; This font is part of a subfamily of fonts that differ only by the size range which each covers, and which share the arbitrary identifier number 3; ID 257 in the name table is the suggested menu name for this subfamily. In this case, the string at name ID 257 is Semibold Condensed; This font is the recommended choice from sizes greater than 13.9-point up through 24-points.
Tag:: Basic Latin
Function:: These fonts support the Basic Latin character set. Each font is Unicode™ encoded, and available in different formats. Please review the product information for each font to ensure it will meet your requirements.