I lived in the same area as the GP, and the thing about not being able to go to the west with regular passports is false. In fact people from all over Yugoslavia went shopping to Trieste in Italy.
The special passports did exist however, and were issued to residents of what used to be the Free Territory of Trieste[0], both in Italy and Yugoslavia. They were established by the Udine Agreement of 1955 (although the border was still disputed and finally settled only in 1975 by the Treaty of Osimo[1]).
I can't find many sources about the special passports online. There is a mention here[2].
Their main advantage was the possibility of using secondary border crossings between Italy and Yugoslavia that had less traffic and shorter queues.
Hi, thanks for clarification, I was not aware that other Yugoslavian residents were able to cross the border as freely as those with the special passport ("Propustnica").
There were similar "passport lite" cross border documents in other parts of Yugoslavia, allowing people living in border regions to easily pass the border but limited to maybe 10-20km in another country. These passes were used by farmers who had pieces of land across the border, or even if land was in the same country the closest road might be through border. I think something like that still exists.
There was a school bus route in Washington that passed through Canada on its way to the school that got really screwed by the post-9/11 stricter border controls.
The special passports did exist however, and were issued to residents of what used to be the Free Territory of Trieste[0], both in Italy and Yugoslavia. They were established by the Udine Agreement of 1955 (although the border was still disputed and finally settled only in 1975 by the Treaty of Osimo[1]).
I can't find many sources about the special passports online. There is a mention here[2].
Their main advantage was the possibility of using secondary border crossings between Italy and Yugoslavia that had less traffic and shorter queues.
[0] https://en.wikipedia.org/wiki/Free_Territory_of_Trieste
[1] https://en.wikipedia.org/wiki/Treaty_of_Osimo
[2] https://www.cambridge.org/core/journals/urban-history/articl...