Rare, formal term for explanatory notes or commentary, similar to 注釈 (ちゅうしゃく). Mostly found in academic or literary contexts.
See also: 注釈
The commentary on this classic text is very detailed.
Rare kanji spelling; 疏 is a variant of 疎. The more common form is 注釈 (ちゅうしゃく).
Variant with 註 instead of 注; both are rare.
Compound of 疏 (そ, 'sparse' or 'commentary') and 注 (ちゅう, 'annotation'). The exact historical derivation is uncertain; the spelling is conventionally associated with explanatory notes.