CJKV Information Processing, 2nd Edition

Glyph Substitution

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feature—at least for higher-end applications, many of which are described at the end of

this chapter.

ere are four basic types of glyph substitution that benet CJKV fonts, many of which

equally apply to any font, regardless of language or script:

Vertical substitution•

Variant substitution•

Ligature construction•

Ligature decomposition•

Vertical substitution is a form of glyph substitution that is expected to take eect when

text is typeset in vertical writing mode. It is almost always considered a functionality that

is invoked automatically when a document is being typeset in vertical mode. With the

exception of standard ligatures, such as  and , the remaining types of glyph substitution

are explicitly invoked by the user.

Character and Glyph Variants

When considering the various types of characters found in CJKV text, one of the most

common types of substitution involves the ability to select dierent forms of a character,

such as traditional, simplied, or variant (/異體字 yìtzì in Chinese,  itaiji

in Japanese, and /󰀙󰌮󰁚 icheja in Korean) forms. Some variants can be dened

more specically, such as JIS78 (JIS C 6226-1978) for Japanese. And, some variants do not

necessarily involve ideographs, such as annotated forms.

Table 7-44 lists several classes of glyph variants, along with appropriate examples for

each using a variety of typeface ...