Hyphenation

Hyphenation is the process of dividing words at line breaks according to language-specific rules, using hyphens to indicate where a word has been split. The goal is to create visually even line lengths and reduce excessive whitespace, while maintaining legibility. A hyphen is a punctuation mark used to join parts of a word or to signal a break; a hard hyphen is printed as a visible character, while a soft or discretionary hyphen marks a potential break and may disappear if the word does not split.

Hyphenation is implemented with language-dependent patterns or dictionaries that define permissible break points within words. These patterns can be used by typesetting systems, word processors, and layout engines. The best-known approach is a pattern-based algorithm, such as TeX's hyphenation system, which derives breakpoints from a set of rules. Exceptions and special cases, such as proper nouns, numbers, or morphology, are often handled by hyphenation dictionaries or style guides.

In practice, hyphenation supports text justification and a more uniform right margin, but must balance break points with readability. Too many hyphens or poorly chosen breaks can impede reading. Different languages have distinct rules, and some scripts have complex syllabification or no straightforward syllable structure. Modern software typically offers automatic hyphenation with configurable settings and, where appropriate, manual control via discretionary or mandatory hyphens.