Where to find it
Open the file → "More actions" → "Download proof of signature"
A signed paper is archived immutable: corrections create a new version, never rewrite the old one. Each signature carries a sealed certificate: who signed, when, from where, and how their identity was checked. What the certificate says is what happened. Every delivery leaves its line in the delivery log, and every act in the file (upload, placement, archive, hold) leaves its line in the activity history.
