One meaning of the Latin word was the governor of a province, such as Pontius Pilate. However, the word also means an agent or proxy, and it is this meaning that applies to the question.

There are a number of functions that one can perform through a proxy. In secular matters, a person usually does this by means of a power of attorney. We can appoint an attorney-in-fact to do something as simple as transferring title on an automobile or as complex as assuming responsibility for all of one’s affairs in the event that one becomes incapacitated. Likewise, in the Church one can act through a proxy in a number of ways. For example, if you are asked to serve as a sponsor at a baptism that is some distance away, you can appoint a proxy to act for you. In fact, one can even marry by proxy (cc. 1104-1105).

Another parallel to our civil system is in class action litigation. The class action mechanism allows one or more members of a class of litigants to sue on behalf of the entire class, provided that they demonstrate that they will adequately represent the class and protect its interests. Although there is no such thing as a class action suit in canon law, many of the benefits of class action litigation can be gained in canonical processes if the members of a group of Catholics designate the same person as procurator. Although a class representative in the civil system must be a member of the group claiming to be injured, the procurator in a canonical matter may be someone outside the group.

In canonical processes, one who acts for another is usually called a procurator rather than a proxy. A person appoints a procurator by signing a document called a mandate. Most of the canons that govern the appointment of procurators also address the function of the advocate. The advocate argues the case and defends the rights of his client, much like a barrister in the British legal system. According to canon 1483:

Often the procurator and advocate are one in the same. This is almost always the situation in appeals to Rome, where a procurator/advocate can sign legal documents in addition to arguing the case on behalf of his client. Until an appeal is taken, however, a client does not usually need an advocate except, of course, in penal processes.

The only qualifications to act as a procurator are, as canon 1483 clearly states, that one have reached the age of majority and be of good reputation. Thus the procurator need not be a Catholic—or baptized at all for that matter—and need not be approved by the bishop. Moreover, he does not have to have a degree in canon law or any other discipline. Although he cannot argue the case, a procurator can appoint advocates, negotiate a settlement, enter into arbitration and lodge an appeal of a decision.

Although a lone individual may appoint a procurator, the primary advantage of a procurator is that he can act on behalf of a group of individuals who have appointed him. This is especially useful in cases involving the closures of parishes, renovations of church buildings and discrimination in administration of the sacraments to children of home schooling parents. Use of a procurator enables the clients in such cases to speak with one voice. Clients are sometimes reluctant to appoint a procurator for fear of losing control over the proceeding. However, such fears are unfounded because a dissatisfied client can revoke his mandate or appoint a substitute procurator at any time.

Even though the procurator has the status of the duly appointed representative of the parties according to canon law, it must be remembered that in many instances the law does not require a pastor or bishop to deal with a procurator any more than he would have to deal with individuals. Therefore, the appointment of a procurator is no remedy to the pervasive and time-honored practice of stonewalling by ecclesiastical authorities. In practice, however, we find that a procurator is more likely to get a response than are individuals acting on their own behalf.