In some societies, the content of the written constitution is fairly consistent with the cultural constitution. Such written constitutions can survive fairly permanently, even though there must be room to amend them all the time. However, even in countries where the written constitution has no problems because it is fairly consistent with the cultural constitution, politics and government are still based a great deal on other, unwritten customs. For example, the custom that the US president is limited to two terms cannot be found laid down anywhere in the US constitution, but is practiced as a custom of politics which is never infringed and can be considered no less sacred than other provisions in the written constitution.