A few points to counradict Pavel.
In the West subdiaconate became considered a major order, which mandated celibacy. It's vestments wre the maniple and tunicle. The subdeacon in the west had the privelege of reading the epistle among other things.
As of the document Pavel speaks of, my take is that the order was abolished, as it was merged with a number of minor orders and no longer considered major. Additionally, some versions of the instructions to the missal assign the tunicle now to the reader, not the acolyte, even though Pavel correctly states that the document says that the acolyte could wear the tunicle and be "called subdeacon".
Acolytes (in the diocese that have them) now often perform functions that were never subdiaconal, such as conducting comunion paraliturgies, benedictions etc, partly as a result of not wanting to ordain deacons I think; and because acolyte is a lay office (politics).
Among the interesting uses I have seen, and possibly more in the spirit of VII than described above was an acolyte reading the epistle and subdeacon's part at a Tridentine mass! However this good work was undone by the abuse of a priest vesting as a deacon and singing that part.
Ned
