This year is one of the few when Easter/Pascha celebrations coincide for Catholics and Orthodox.
On Saturday's Easter Vigil worldwide, catechumens and candidates who went through the "yearlong" Rite of Christian Initiation of Adults (RCIA) will be received into full communion with the Catholic Church.
The RCIA is an "ancient" Church tradition resurrected (pardon the pun) in the Catholic Church pursuant to Vatican II.
In the United States, the USCCB annually comes out with selected "profiles" of converts to the Catholic Church in the United States. The USCCB descibes this year's crop, as culled from the diocesan reports nationwide:
Thousands Joining Catholic Church Holy Saturday; Among Them Priest’s Father, Family of Ten
WASHINGTON (April 3, 2007)—Tens of thousands of people will join the Catholic Church on Holy Saturday, April 7, through the Rite of Christian Initiation of Adults (RCIA).
Many of them, known as catechumens, participated in the Rite of Election with their bishops at the beginning of Lent and will be baptized, confirmed and receive Holy Eucharist for the first time on Holy Saturday. Those known as candidates, who were already baptized but did not receive further catechetical formation, have been pursuing an adapted version of formation and will complete their initiation. Other candidates, who were baptized as members of another Christian community, will be received into full communion with the Catholic Church.
Full story at:
http://www.usccb.org/comm/archives/2007/07-054.shtmlDo the non-Catholic Eastern Churches (Orthodox, Orientals, and Assyrians) also have a comparable ceremony during Easter Vigil for the reception of converts into their respective Churches?