‘夹注’ (jiā zhù) literally means ‘inserted annotation’: ‘夹’ (jiā) means ‘to insert between’ or ‘to sandwich’, and ‘注’ (zhù) means ‘annotation’ or ‘note’. Together, they refer specifically to interlinear annotations — explanatory notes written directly above or between lines of classical or difficult Chinese text, commonly used in traditional philology, historical documents, and annotated editions of ancient texts like the Confucian classics or medical manuscripts. These notes clarify pronunciation, meaning, variant characters, or grammatical function.

Unlike footnotes or endnotes, 夹注 appear inline — often in smaller font or different script — embedded within the main text flow. They are especially frequent in scholarly editions intended for learners or researchers, where precise textual interpretation is essential. While rare in modern everyday writing, 夹注 remain vital in academic publishing, paleography, and digital humanities projects involving pre-modern Chinese sources.