noun
top-secret data; confidential documents
Refers to documents or data marked as highly confidential, often used in business or government contexts.
このファイルにはマル秘資料が含まれているので、取り扱いに注意してください。
This file contains confidential documents, so please handle it with care.
機密文書 is a more formal term for classified or secret documents, often used in legal or military contexts, while マル秘資料 is a common term for confidential business or administrative documents.
Compound of マル秘 (maruhi, 'confidential' or 'secret', from 丸秘 with the circled マル symbol) and 資料 (shiryō, 'materials' or 'documents').