A liberal exit–entry regime for foreigners
• Already in 1951–52 Yugoslavia unilaterally abolished visas for Romanian, Hungarian, Bulgarian and Polish tourists.
• Once inside Yugoslavia, those “tourists” could apply for asylum at Western embassies in Belgrade, Zagreb or Ljubljana; the Yugoslav authorities usually granted exit permits within days.
• By the late 1950s Western intelligence estimated that 6 000–8 000 East Europeans a year were using this route, a figure that rose after the 1956 Hungarian revolt.

Safe transit for ethnic-German remigration (1950s–1970s)
• Bonn and Belgrade negotiated agreements that let ethnic Germans from Romania, Hungary and the USSR cross Yugoslavia by rail to Austria and West Germany.
• Over 130 000 people left under these protocols; the trains were sealed in Yugoslav territory so Warsaw-Pact security could not touch them.

Post-1960 guest-worker corridor to Western Europe
• After Yugoslavia signed labour-recruitment treaties with West Germany, Austria, France and Sweden (1964-69), Belgrade allowed citizens of neighbouring socialist states to obtain Yugoslav papers (often on the basis of distant kinship or bribery) and then join Yugoslav “gastarbeiter” flows.
• Western German records list more than 40 000 “Yugoslavs” who arrived in 1967-72 but spoke Hungarian, Romanian, Czech or Polish as their first language—clear evidence of secondary migration.