Within Roman Catholicism this term can also mean a particular type of church building, for which see here.
The term national church is usually a reference to a church organization in Christianity that claims pastoral jurisdiction over a nation. Sometimes the head of state is considered the ceremonial head of the national church, with the church not endorsing itself as the state religion. The term should not be confused with established church (state church): a national church differs from a state church in that a national church does not necessarily need to be officially endorsed by the state, and even may be persecuted by the government (as Orthodox churches were persecuted under communist regimes).
Romania ? none; traditionally the Romanian Orthodox Church has seen itself as the national church, but since 2004 the ROC resigned to any claim of this status to conform with the country's secular constituition.