# Standard OpenType Font Features Libertinus supports several OpenType features. Some are enabled by default (`-`) others have to be opted in (`+`). - Small Caps: `+smcp` and `+c2sc` - Ligatures and Contextual Alternates: `-liga`, `+hlig`, `+dlig`; `-calt` - Kerning: `-kern` - Capital Spacing: `+cpsp`, `case` - Slashed zero: `+zero` - Numerals: `-tnum`, `+pnum`, `-lnum`, `+onum`, `+pnum+onum` - Vulgar fractions: `+frac` - Subscripts and Superscripts: `+sinf`, `+sups` - Diacritic marks: `-mark`, `-mkmk` - Stylistic alternates: `+salt` Most of these can be accessed by high-level CSS properties or values and by GUI controls in DTP software. ## Cased forms: `+case` All digits and some punctuation characters (i.e.��parentheses, guillemets and hyphen) use shapes that better fit with all-uppercase text (`.cap` or `.sc`). ## Standard ligatures: `-liga` In serif faces, the Latin lowercase letter sequences *����*, *����i*, *����j*, *����k*, *����l*, *��h*, *��i*, *��j*, *��l*, *��s*, *��t*, *ff*, *ffh*, *ffi*, *ffj*, *ffk*, *ffl*, *fh*, *fi*, *fj*, *fk*, *fl*, *ft* form default ligatures. In sans-serif faces, only the Latin lowercase letter sequences *ff* (also if the second one has a shortened head) and *ft* form default ligatures. The related feature `clig` is not used. The respective CSS property is `font-variant-ligatures` with the value `common-ligatures` (or `no-common-ligatures`). ## Discretionary and Historical Ligatures: `+dlig`, `+hlig` The only historical ligatures supported are Latin lowercase *st* and *ct* in all faces. In all faces, Latin lowercase letter sequences *tt* and *tz* form discretionary ligatures. Only in serif faces (i.e.��non-sans-serif), Latin letter sequences *Th*, *ck* and *ch* also form discretionary ligatures. These can all be manually forced by using ZWJ (U+200D) between letters when just the default feature `liga` is active. The respective CSS property is `font-variant-ligatures` with the values `discretionary-ligatures` and `historical-ligatures`. ## Contextual alternates: `-calt` In all faces, the Latin capital and small-capital letter *Q* gains a long tail if followed by either lowercase or small-capital letter *u* or *v*. The Latin lowercase letter *f*, even when part of the ligature *ff*, has a shortened head if followed by closing parentheses, top quotation mark, lowercase letter with ascending left leg, lowercase letter with diacritic mark above or uppercase letter not starting with a leg or stem on the left. The related feature `clig` is not used. The respective CSS property is `font-variant-ligatures` with the value `contextual` (or `no-contextual`). ## Localized alternates: `locl` For Serbian and Macedonian, in all faces, the Cyrillic lowercase letter be *��* and in italic faces, the Cyrillic lowercase letters ghe *��*, gje *��*, de *��*, pe *��* and te *��* are replaced by alternate glyphs. For Scandinavian languages, because of preferences in Sami typography, the Latin uppercase letter Eng *��* uses a alternative glyph, cf.��`ss07`. For Turkic languages, ligatures where the Latin lowercase letter *i* is the second part are deactivated, i.e.��*fi*, *ffi*, *��i* and *����i*. The small-capitals handling of *i* / *��* does not depend on `locl`, but is part of `smcp` (and `c2sc`). ## Numerals: `-tnum`, `+pnum`, `-lnum`, `+onum`, `+pnum+onum` Except for Libertinus Math, the standard digits can be forced to *old-style* forms (with ascenders and descenders) with `onum` (`.taboldstyle`), to default *lining* forms with `lnum`, to *proportional* forms with `pnum` (`.fitted`), to *tabular* (fixed-width) forms with `tnum`. The latter two also apply to Euro *���* and Yen *��* currency symbols and trump the other features. The respective CSS property is `font-variant-numeric` with the values `oldstyle-nums`, `lining-nums`, `proportional-nums` and `tabular-nums`, respectively. ## Vulgar fractions: `+frac`; `subs`, `sups`; `sinf` The same sets of inferior/subscript and superior/superscript glyphs are used for various features. The respective CSS property for `frac` is `font-variant-numeric` with the value `diagonal-fractions`. The value `stacked-fraction` is not supported. # Custom OpenType Font Features: Stylistic Sets ## Stylistic alternates: `+salt` For non-sans-serif faces, Latin uppercase letters *J*, *K*, *R* and *W* use alternate glyphs (`.alt`). For small-caps faces, Latin lowercase letters *a*, *q*, *��* and *��* use alternate glyphs (`.scalt` etc.). In all faces, Latin uppercase letters *Q*, eng *��* and eszet *���*, Latin lowercase letters *h*, *y* and Eszet *��*, Greek lowercase letters Beta *��*, Theta *��*, Kappa *��* and Phi *��*, Cyrillic lowercase letter Be *��* and the ampersand *&* use alternate glyphs, cf.��`calt`, `ss03`, `ss04`, `ss06`, `ss07`, `locl`. The respective CSS property is `font-variant-alternates` with the value `stylistic(<feature-value-name>)`. ## Stylistic Set 1 `ss01` *Low diaeresis on ���A���, ���E���, ���O���* Intended for German, the umlaut dots above the Latin capital letters *A* and *O* (*��*, *��*) are moved further apart while the ones above *U* (*��*) are put closer together. ## Stylistic Set 2 `ss02` *Swashy ���J��� ���K��� ���R���* A bit more swashy, cursive look with elongated tails for Latin uppercase letter *K* and *R* and a left-hand horizontal top for *J*. This does not apply to sans-serif faces. ## Stylistic Set 3 `ss03` *���double s��� to two ���s���* All variants of German eszett (lowercase *��*, uppercase *���* and small-capital) are rendered as round-s digraphs *SS/ss* instead, very applicable to Swiss German texts. ## Stylistic Set 4 `ss04` *Upper case ���double s��� to two ���S���* Only the uppercase German eszett *���* is rendered as a round-s digraph *SS*; subset of `ss03`. ## Stylistic Set 5 `ss05` *Crossed ���W���* Latin uppercase letter *W* is rendered as a ligature of two *V*, i.e.��the middle verticals are longer, as used in the Wikipedia logo. This does not apply to sans-serif faces. ## Stylistic Set 6 `ss06` *Swash ���&���* The ampersand *&* is rendered as an *et* ligature. ## Stylistic Set 7 `ss07` *Swap ���Eng��� forms* The uppercase letter Eng *��*, i.e.��an *N* with a descending tail on the right leg, uses the capital *N* glyph as its base instead of the default enlarged lowercase *n* glyph. The localized `locl` UC Style for Sami is changed the other way around.