Switched bills of lading. A country may not have diplomatic relations with another country but traders in one or the other may wish to have goods transported between these countries.
Subject approval of relevant authority. This affects the enforceability of a charter if the ship's certification and cargo handling capabilities are required to meet with official approval. For example, if a vessel is not provided with a valid "document of authorisation" it may not be allowed to load grain and the charter may depend on permission being granted to load.
Subject shippers' approval. Like the previous restriction, this is also a "condition precedent" which can cause the fixture to fail to be binding if the shippers do not accept the ship to load the cargo. Again, also like the previous restriction, this can require a third party's approval before a charter between the owner and the charterer becomes binding.