The Eastern Orthodox communion is composed of several different churches, most of them arranged by country. There are the Russian Orthodox Church, the Greek Orthodox Church, the Serbian Orthodox Church, the Orthodox Church in America, and others. All of these churches are in full communion.
Is it meaningful for a person to “convert” or “transfer” from one to the other? For example, if a Greek citizen who is a member of the Greek Orthodox Church moves to Russia, would he be expected or required to “convert” or formally transfer his membership to the Russian Orthodox Church? Is there even a procedure for this, or does the very fact that he has moved into a Russian Orthodox diocese mean that he is now under the aegis of the Russian Orthodox Church as a full participant?