It is a legal distinction for temporary workers in a very large number of countries, regardless of the name. 4-5 years is pretty common, then you have to apply again. Australia for instance uses 4 years. Hence a “posting” for staff is often 4 years in a lot of companies. And given the extra costs of doing so, pay tends to be considerably above the same job locally. It is actually hard to get people to do it these days due the impact on partners in particular. The traditional husband with trailing wife died a death in the 90’s. For many couples it is value negative. You end up with with a lot of commuting, and I can tell you flying to Miri every month isn’t the cheerful thought you might think it should be.