Dutch Indies Specimen? Cards?

Hello everyone, I have these cards with stamps of the Dutch Indies The are stuck onto the cards, which are made of thick paper and the stamps are discribed in French text(UPU language). They look like cards that would be issued to other countries, so that they have an idea on what stamps are used in the Dutch Indies. The cards appear to be from around 1945. The problem is that the 1940 Red cross stamp was no longer valid in 1945 and the 1941 series misses 1 stamp. Has anyone ever seen a similar kind of card used and has some information on its purpose. Thanks Johan.

Someone recently showed some similar Chinese items. I think these were probably part of a booklet presented to attendees at a UPU meeting including stamps issued since the previous meeting.

Thanks Geoffha.

The Chinese examples you mentioned do look similar to the D.I. ones I have. I will investigate further in the UPU direction.

johan.