Design Nomenclature / Type

Ligature

Also called liga, standard ligature, discretionary ligature, dlig

One glyph replacing a sequence, applied by OpenType's GSUB table. Standard ligatures (liga) fix collisions the letters make on their own — fi, ffl, where the f's terminal hits the i's dot — and are on by default. Discretionary ligatures (dlig) are ornamental: ct, st, Th. They are off by default for good reason.

Three rows. 'Unligated' sets fi, ffl, ct and st glyph by glyph at their raw advances, so nothing joins. 'Standard (liga)' sets fi and ffl — Georgia carries these as real Unicode glyphs, so the join is set rather than simulated. 'Discretionary (dlig)' sets ct and st plain, with a note saying they have no Unicode form: a dlig lives only inside the font's table, which an SVG cannot reach, so the arching stroke the entry describes is not on show.

In practice

dlig at text size is noise; at display size it can be the point. Note ligatures can break text selection and search in some PDF pipelines, and that ligating across a word boundary — as in some monospace coding fonts — is a different trick entirely.

Not to be confused with

How this term connects

DevanagariKerningOpenTypeRight-to-leftScriptSmall capsTerminalLigature
Related Confused with