Opens a document (.pdf, .docx, .xlsx, .pptx) and shows what it keeps in memory: author, dates, software, company, and for Office files the tracked changes and comments. Paste the address of a Lab document or choose a file (it is sent nowhere).
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In real life: exiftool, FOCA, Word's Document Inspector. A PDF keeps the author and the software that created it; a Word file is an archive of XML files where text « deleted » with track changes stays in it in full.