Nationality law is the
law in each country and in each
jurisdiction within each country which defines the rights and obligations of
citizenship within the jurisdiction and the manner in which citizenship is acquired as well as how citizenship may be lost. A person who is not a citizen of the country is generally regarded as a foreigner, also referred to as an
alien. A person who has no recognised nationality or citizenship is regarded as
stateless. By
international custom, each
sovereign state has the right to determine who it will recognise as its nationals and citizens. Such determinations may be made by custom,
statutory law, or
case law (precedent), or some combination. In some cases, the determination may be governed by
public international law—for example, by
treaties and the
European Convention on Nationality.