In the days before WIS that was how the service manuals were distributed. It was a very prevalent system for large scale storage and distribution of data.

We used a similar system for engineering drawing archival at a company I worked for in the 90s. When everyone still had drafting boards. I came in at the beginning of the CAD era but still had to occasionally modify existing hand drawings. That is a dying art now.

Instead of many drawings on one sheet of film (like you see in the video) it was one drawing on a Hollerith card. They were called Aperture cards because the film was inserted into the card on the left side. The right side had the traditional punching system which encoded the drawing number. We had a room that was full of file drawers containing those cards.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech