supplementary information; additional information
Neutral term for extra details added to clarify or complete something. Common in formal, technical, and everyday contexts.
I added a graph as supplementary information.
This document lacks supplementary information.
追加情報 emphasizes information added later or on top of existing content, while 補足情報 focuses on filling gaps or providing completeness.
Compound of 補足 (supplement) and 情報 (information). The exact historical derivation is uncertain, but the meaning is transparent from its components.