Infocom and other companies offered optional commercial feelies (physical props associated with a game). The tradition of 'feelies' (and the term itself) is believed to have originated with "Deadline" (1982), the third Infocom title after "Zork I" and "II". When writing this game, it was not possible to include all of the information in the limited (80KB) disk space, so Infocom created the first feelies for this game; extra items that gave more information than could be included within the digital game itself. These included police interviews, the coroner's findings, letters, crime scene evidence and photos of the murder scene.