This may not be common knowledge, but The Cure once officially contributed music to a documentary about the port of Rotterdam. It could very well be that the band themselves have forgotten about this. The story goes that two Dutchmen working on the film took a boat to England, probably in the winter of 1980/81, and had a meeting at The Cure’s Fiction label offices in London to discuss music for the documentary. For a fair price they bought a tape of new music by The Cure to use.
At that time the band were working on the Faith album. It turned out that the tape for the documentary included songs that later ended up on that album. It is not easy to hear, but my guess is that these are advanced (instrumental) demos. Possibly almost final backing tracks. The songs in question are The Funeral Party (at approx. 5:30), The Drowning Man (at approx. 14:15) and All Cats Are Grey (at approx. 19:00 and 21:20 throughout the end credits). The Drowning Man seems to be in a different key or tempo. But that may have been done by the filmmakers.
As for the documentary itself, it is a kind of promotional film for Rotterdam’s harbour. People in various positions at the port talk about their work. With today’s eyes, it may seem a little strange how this particular music could be relevant to the subject of the documentary. But I think it fits the era well. The documentary was broadcast on Dutch public television. You can watch it (or at least part of it) here.