The Missionaries of Africa actually become Missionaries of Africa by taking the Missionary Oath. This is a solemn promise to dedicate our lives to the Church’s mission in Africa according to the rules of the Society and in obedience to the Superior General. This Oath is taken for life. Both Brothers and Deacons/Priests take the same Oath.
Normally we celebrate the 25, 50 and 60 years of Oath. When God grants we also celebrate 70 and 75 years, although that tends to be rare.