The ordinary minister who does the job of the altar server is an Instituted Acolyte. Only men can be instituted as acolytes, not women. Every man who is ordained as a deacon should first become an Instituted Acolyte for at least six months (Code of Canon Law, canon 1035). The General Instruction of the Roman Missal (GIRM) has: “100. In the absence of an instituted acolyte, there may be deputed lay ministers to serve at the altar …”.
So if there is a Mass with 100 instituted acolytes, but only room in the sanctuary for seven, it would be wrong if any of the seven were not instituted acolytes. The extraordinary ministers would be doing the job of the ordinary ministers when they are available.
Similarly the first reading is proclaimed by an Instituted Lector. GIRM 101 “In the absence of an instituted lector, other lay people may be deputed to proclaim the readings from Sacred Scripture, …”.
Similarly the intentions of the Prayer of the Faithful are read by the deacon. GIRM has the section “Mass with a Deacon” “177. After the introduction by the Priest, it is the Deacon himself who announces the intentions of the Universal Prayer, usually from the ambo.”
So if the church wanted to further emphasise that there are ordinary and extraordinary ministers for these tasks it may come up with terminology to do so.
– Extraordinary Ministers for Serving at the Altar
– Extraordinary Ministers for Proclaiming the Readings from Sacred Scripture Before the Gospel
– Extraordinary Ministers for Announcing the Intentions of the Prayer of the Faithful
The term “Extraordinary Ministers of Holy Communion” reminds those ministers that they should only distribute communion when there are not enough ordained ministers. These terms would remind other ministers that they should only do those tasks in the absence of the ordinary minister.