The list commonly given in the United States (it has varied in different places and times) is a result of the 3rd Council of Baltimore as the Catholic Encyclopedia notes:
•to keep the Sundays and Holy Days of obligation holy, by hearing Mass and resting from servile work;Coincidentally, I came across an interesting discussion of the issue while looking for something else. This comes from an 1886 number of the Irish Ecclesiastical Record (3rd series, vol. VII, pg. 160). Note that "pastor's second paragraph refers to the different listings of the Precepts of the Church as recounted in the Catholic Encyclopedia article linked above.
•to keep the days of fasting and abstinence appointed by the Church;
•to go to confession at least once a year;
•to receive the Blessed Sacrament at least once a year and that at Easter or thereabouts;
•to contribute to the support of our pastors;
•not to marry within a certain degree of kindred nor to solemnize marriage at the forbidden times.
The Fifth Precept of the Church
"The faithful are instructed by the Catechism that they are bound in conscience and in justice under the above precept to contribute to the support of their Pastors. "Would you therefore kindly inform me on the following points:—(a) Who are bound by it? Are (1) married women who may happen to be possessed of private means? Are (2) grown-up children who, though living with their parents, have a small salary or allowance of their own? Are (3) domestic servants, labourers, clerks, shop-assistants, et hoc genus omne, who find it a pretty sharp struggle to keep afloat? (b) How much are they bound to contribute? And (c) When or how often are they so bound?
"It is noteworthy that this precept, grounded, as the Catechism states, on 1 Cor. ix. 14, is only to be found in poor, generous, Ireland; it is unknown in England, nor is it to be met with amongst the "praecepta Ecclesiae" in any handbook of theology I have "come across. It is perhaps due to this fact that so many Priests differ in answering, if indeed they answer at all, the above questions.
St. Paul in the passage mentioned by our correspondent states and proves conclusively that those who preach the Gospel have a right to live by the Gospel. Such is the ordinance of Christ. Such too is the law of nature. If the minister of grace spends his life in attending to the spiritual wants of the faithful, those who expect and benefit by his holy services are assuredly bound, one and all, according to the means of each, to supply his temporal support. This is not merely a duty of sacrificing something to acknowledge God's supreme dominion, from a motive of religion; it is proximately a sacred debt of justice arising out of a solemn contract implied in the reception of baptism. The Church too, for her part, provides pastors on the understanding that the faithful will, as far as possible, secure them becoming maintenance in return for spiritual services. This, no doubt, is only an aspect ot the natural obligation. It suffices, however, to show how the Church could withdraw for a time .the ministrations of her priests, if no better means could be found of compelling her children to discharge the duty of maintaining their pastors. Happily, as our correspondent so truly hints, in Ireland there is only question of who in particular come under the law proclaimed in our Catechism. The commandment is intended to enforce by ecclesiastical authority in a definite way an obligation that comes already in substance from the natural and divine law. Our forefathers had stored permanent support in benefices and foundations for the priests of the land; but alien rapacity devoured the sacred inheritance and made it necessary for Irish bishops and councils to call on the people for such provision as was possible in the ruin that supervened. The system, in one sense voluntary, is in truth a modified application of tithe legislation and must accordingly be in some measure obligatory. To explain this inference we must go back a little.
In the first centuries, though all priests could not hope to earn their bread by manual labour like St. Paul, the contributions of the faithful towards clerical support, were, for the most part, voluntary. First-fruits (primitiae) and offerings (oblationes), which were meant to meet the expenses of public worship and feed the poor, conjointly with maintaining the clergy, came without the asking. It was a time when charity gave more than justice could demand. But after some years the Church thought well to legislate on the subject, and enforce by her Canons the payment of certain customary contributions. Soon first-fruits fell into disuse, but the offerings of various kinds, some free, others of obligation, continued as before, and tithes were almost everywhere imposed. These tithes were of three kinds, prædial, mixed and personal, the latter falling on the produce of industry and labour and accordingly affecting all classes of persons. In Ireland the law began with the Synod of Kells before, and the Synod of Cashel after, the English Invasion. Although the Council of Trent endeavoured to protect them, tithes have gradually passed, in most countries, out of the hands of the Catholic priesthood. The general establishment of benefices and foundations had rendered them less necessary than before, and the hostility of governments hastened their disappearance. As a rule then the law of paying a fixed proportion of yearly produce has gone into disuse, or, as with ourselves, though it may still run "to pay tithes to the lawful pastors of the Church," it means to pay the dues fixed as a yearly contribution to our true pastors, since tithes properly so-called have been seized for another purpose. This is the least the Catechism implies, and we are now free to examine the precept in detail.
1. In Ireland the extent of contributions has wisely been left in great measure to the generosity of the faithful. Obligation seems to affect only the fixed dues or collections. Hence everything else is perfectly free so long as the priest is suitably maintained. But should he fail to derive from the appointed stipends such a living as becomes his position, the Commandment certainly intends to enforce the obligation that would at once arise from the natural law, and bind every parishioner according to his means, to help in supplying the pastor's wants.
2. Who are bound by the Commandment? As a rule those who are on the priest's list for annual stipends. The heads of families, male and female, are of the number. So in some instances are officials, clerks, and even servants. But usage varies for these classes, and everywhere allowance is made for peculiar circumstances, such as their means, the distance of their employment from home, the kind of contribution demanded.
3. Excusing causes are often present, and even if there he nothing to justify a refusal, we must think twice before proclaiming our rights. Voluntary offerings on other occasions may cover the obligation, or failure may be of rare occurrence. Again, the charm of a clergy maintained by the free contributions of the people should not be broken for a trifle. It is much better to keep the question of right in the back-ground. No reasoning on the subject, at least in a public and disputatious way, would improve the spirit of the faithful in regard to clerical dues. What is true of the people at large, on this head, is also applicable to the case of individuals. Unless there be good hope of success it is useless to proclaim and insist on rights in justice. At the same time laymen who know their obligations and refuse to discharge them, without any excuse or reason for supposing that the priest does not press his right, are plainly committing an offence against God, His Church, and the neighbour. But, owing to the voluntary character that in some measure has passed, to the whole system by which the priesthood is supported, a materia gravis is not so readily reached in these transactions as in ordinary dealings.