original notes; author's footnotes
Refers to annotations or footnotes provided by the original author, as opposed to those added by an editor or translator.
The original notes in this book are very detailed.
翻訳版では、原注に加えて訳注も付いている。
In the translated edition, translator's notes are added in addition to the original notes.
脚注 is a general term for footnotes, regardless of who wrote them.
Standard kanji spelling; 注 is the modern simplified form.
Traditional kanji form using 註; less common in modern writing.
Compound of 原 (original) and 注 (annotation).