This feature introduces support for the font-language-override CSS property in Chromium. The property allows developers to override the system language used for OpenType glyph substitution by specifying a four-character language tag directly in CSS. This enables fine-grained typographic control, particularly useful for multilingual content or fonts with language-specific glyph variants.
Currently, Chromium relies on system-level language settings for OpenType glyph substitution, which may not always align with the author's intent. By exposing font-language-override at the CSS level, developers gain direct control over language-specific font behavior, improving rendering accuracy and consistency across platforms. This feature is already supported in Firefox, enhancing interoperability.