- auto: Enables automatic hyphenation of words based on line-break
opportunities within words or by a “language-appropriate hyphenation
resource”
- manual: Enables hyphenation of words based only on line-break
opportunities within words
- none: Prevents hyphenation
The W3C points out that you must declare a language using the
HTML lang or XML xml:lang attributes for correct automatic hyphenation to
occur.
That means if your entire HTML document is in the same language
(English, for example) and you want to enable automatic hyphenation, add
the attribute to your HTML element or doctype declaration, such as:
<!DOCTYPE html>