A report tells the players what happened. The folder it came in tells them who else has been reading it: a name on the charge-out slip that nobody at the table has heard of, dated a week after the case was closed, is a lead nobody had to say out loud.
The cover carries the agency, the file number, the case, the dates it was opened and closed, the officer in charge, a status stamp across the front and a slip on which everyone who took the file out signed for it. A date left empty keeps its line, so an open case looks open. The second page is the summary sheet clipped inside: a photograph of the subject, the persons involved and their part in it, the case so far, sized to the room the page leaves, and an index of the reports and exhibits the file holds.
A 1920s police department’s manila folder with its tab and a red rubber stamp; an Eastern Bloc security service file with the list of every officer who read the material; a modern federal file cover between two classification bands; a cyberpunk corporate security dossier with its access log; and a fantasy city watch’s roll, tied with a ribbon under the magistrate’s seal. A4 at 300 DPI.
The reports inside are an Official Form, the print the photograph box waits for is a Photograph, and the evidence log that grows beside the file is a Register.