Handbook of Liturgical Practice of the Russian Church Abroad
In smaller parishes, where the number of names sent into the Altar by the faithful via commemoration lists and books makes it possible, the Priest will commemorate all the names himself: reading each name and removing a particle from the prosphora for each (see the entry on how this is to be done properly).
In larger parishes or monasteries, where it is entirely conceivable that the names presented for commemoration will run into the many hundreds or even many thousands, it is the custom of the Church Abroad that pious Altar servers so blessed by the Priest to do so, may join him in th reading of the names of the living and departed from the commemoration lists, while the Priest removes particles from the prosphora. This is a longstanding practice and part of the tradition throughout the whole of the Orthodox world.
Altar servers selected by the Priest to aid him in this way will be so chosen based on his observance of their piety and comprehension of the spiritual work being undertaken — and thus he will first educate them fully, so that they understand what they are doing in so reading these names. The Priest is not to select small boys for this labour, but the more mature amongst his Altar servers.
Those reading names for commemoration do so while standing near the table of oblation whilst the Priest removes particles from the loaves. They do not begin reading names before the Proskomedia has been served, nor do they continue reading any names that may be sent into the Altar after the Great Entrance (these are instead saved for the next celebration of the Divine Liturgy).