computer science

List of typographic features

List of typographic features is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of typographic features rather than just read about it. In short: Typographic features made possible using digital typographic systems have solved many of the demands placed on computer systems to replicate traditional typography and have expanded the possibilities with many new features. Three systems are in common use: OpenType, devised by Microsoft and Adobe, Apple's Apple Advanced Typography (AAT), and SIL's Graphite.

Key takeaways

List of typographic features belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of typographic features to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of typographic features from memory before moving on to harder problems.

Reference excerpt

Typographic features made possible using digital typographic systems have solved many of the demands placed on computer systems to replicate traditional typography and have expanded the possibilities with many new features. Three systems are in common use: OpenType, devised by Microsoft and Adobe, Apple's Apple Advanced Typography (AAT), and SIL's Graphite. The lists below provide information about OpenType and AAT features. Graphite does not have a fixed set of features; instead it provides a way for computer fonts to define their own features.

OpenType typographic features The OpenType format defines a number of typographic features that a particular font may support. Some software, such as Adobe InDesign, LibreOffice/OpenOffice, or recent versions of Lua/XeTeX, gives users control of these features, for example to enable fancy stylistic capital letters (swash caps) or to choose between ranging (full-height) and non-ranging (old-style, or lower-case) digits. Some web browsers also support OpenType features in accordance with the CSS Fonts Module Level 3 specification, which allows OpenType features to be set directly via the font-feature-settings property, or indirectly by means of higher-level mechanisms. The following tables list the features defined in version 1.8.1 of the OpenType specification. The codes in the "type" column are explained after the tables. OpenType features may be applicable only to certain language scripts or specific languages, or in certain writing modes. The features are split into several tables accordingly.

Features primarily intended for or exclusively required by South-Asian alphasyllabaries (Indic/Brahmic)

Features primarily intended for or exclusively required by East-Asian tetragrams (Chinese, Japanese, Korean)

Features primarily intended for or exclusively required by West-Asian (Semitic, Arabic) and other cursive scripts or fonts

Features intended for bicameral [cased] alphabets (Latin, Greek, Cyrillic, etc.)

Features depending on writing direction

Features intended for digits and math

Ligation and alternate forms features intended for all scripts

Positioning features intended for all scripts

Special features intended for all scripts

Legend of substitution and positioning codes Below are listed the OpenType lookup table types, as used in the "type" column in the above tables. S stands for substitution, and P stands for positioning. Note that often a feature can be implemented by more than one type of table, and that sometimes the specification fails to explicitly indicate the table type.

AAT typographic features Features that take one value, mutual exclusive from the rest:

Annotation nalt No Annotation Box Annotation Rounded Box Annotation Circle Annotation Inverted Circle Annotation Parenthesis Annotation Period Annotation Roman Numeral Annotation Diamond Annotation Character Alternatives No Alternates ... rand; aalt, calt, falt, jalt, salt, ssXX, hkna/vkna, rtla, vrt2 Character Shape half, ruby; ljmo, vjmo, tjmo Traditional Characters trad Simplified Characters smpl JIS 1978 Characters jp78 JIS 1983 Characters jp83 JIS 1990 Characters jp90 Traditional Characters, Alternative Set 1...5 tnam, hojo, nlck Expert Characters expt, locl CJK Latin Spacing Half-width hwid, halt Proportional pwid, palt Default Latin Full-width Latin fwid Cursive Connection init, medi/med2, fina/fin2/fin3; haln, nukt, vatu, rphf, pres, pstf/psts Unconnected isol Partially Connected calt, clig Cursive curs Design Complexity Design Level 1 Design Level ... Diacritics Show Diacritics Hide Diacritics Decompose Diacritics ccmp Fractions No Fractions Vertical Fractions afrc Diagonal Fractions frac, dnom, numr Ideographic Spacing Full Width fwid Proportional pwid, palt Kana Spacing Full Width fwid Proportional pwid, palt Letter Case case Upper & Lower Case All Caps All Lower Case Small Caps smcp, pcap Initial Caps c2sc, c2pc Initial Caps and Small Caps Number Case Lower Case Numbers onum Upper Case Numbers lnum Number Spacing Monospaced Numbers tnum Proportional Numbers pnum Ornament Sets ornm None Dingbats Pi Characters Fleurons Decorative Borders International Symbols Math Symbols mgrk Text Spacing Proportional pwid, palt Monospace fwid Half-width hwid, halt Normal Vertical Position No Vertical Position Superiors sups Inferiors subs, sinf Ordinals ordn Features that take a number of values:

Ligatures Required Ligatures rlig, clig Common Ligatures liga Rare Ligatures hlig, dlig Logos Rebus Pictures Diphthong Ligatures Squared Ligatures Squared Ligatures, Abbreviated Mathematical Extras Hyphen to Minus (‘-’ → ‘−’) Asterisk to Multiply (‘*’ → ‘×’) Slash to Divide (‘/’ → ‘÷’) Inequality Ligatures Exponents Smart Swashes swsh, cswh Word Initial Swashes Word Final Swashes Line Initial Swashes Line Final Swashes falt Non-Final Swashes jalt Style Options No Style Options Display Text size Engraved Text Illuminated Caps Titling Caps titl Tall Caps Transliteration locl No Transliteration Hanja to Hangul Hanja to Hangul, Alternative Set 1...3 Hiragana to Katakana Katakana to Hiragana Kana to Romanization Romanization to Hiragana Romanization to Katakana Typographic Extras Hyphens to Em Dash (‘--’ → ‘—’) Hyphen to En Dash (‘-’ → ‘–’) Unslashed Zero zero Form Interrobang (‘!?’/‘?!’ → ‘‽’) Smart Quotes (‘"'"’ → ‘“’”’) Periods to Ellipsis (‘...’ → ‘…’) Binary features that can only be turned on:

All Typographic Features Linguistic Rearrangement Overlapping Characters Vertical Substitution

See also List of typographical symbols and punctuation marks

External links "Layout tag registry", OpenType spec, Microsoft, 9 December 2021 "Font Feature Registry", Fonts, Apple – AAT layout tag specs OpenType User Guide for Adobe Fonts (PDF), Adobe An Introduction to OpenType Substitution Features, I love typography

Worked examples

Example 1 — a first encounter with List of typographic features

Start with the simplest possible case. Write down what List of typographic features claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of typographic features before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of typographic features ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of typographic features

In research: List of typographic features appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of typographic features in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of typographic features is common in secondary-school and first-year university syllabi. It links to neighbouring topics Design-related lists, Digital typography, Software features, so understanding it makes those chapters shorter.
In everyday life: Look for List of typographic features outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study List of typographic features in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of typographic features means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of typographic features out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of typographic features in simple terms?

Why does List of typographic features matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of typographic features?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of typographic features.