Chapter II: Conditions for Holding Sunday Celebrations in the Absence of a Priest
18. Whenever and wherever Mass cannot be celebrated on Sunday, the first thing to be ascertained is whether the faithful can go to a church in a place nearby to participate there in the eucharistic mystery. At the present time this solution is to be recommended and to be retained where it is in effect; but it demands that the faithful, rightly imbued with a fuller understanding of the Sunday assembly, respond with good will to a new situation.
19. The aim is that the riches of Sacred Scripture and of the Church's prayer be amply provided to the faithful gathered on Sundays in various ways even apart from Mass. For the faithful should not be deprived of the readings that are read at Mass in the course of a year, nor of the prayers of the liturgical seasons.
20. Among the forms of celebration found in liturgical tradition when Mass is not possible, a celebration of the word of God is particularly recommended,  and also its completion, when possible, by eucharistic communion. In this way the faithful can be nourished by both the word of God and the body of Christ. "By hearing the word of God the faithful learn that the marvels it proclaims reach their climax in the paschal mystery, of which the Mass is a sacramental memorial and in which they share by communion."  Further, in certain circumstances the Sunday celebration can be combined with the celebration of one or more of the sacraments and especially of the sacramentals and in ways that are suited to the needs of each community.
21. It is imperative that the faithful be taught to see the substitutional character of these celebrations, which should not be regarded as the optimal solution to new difficulties nor as a surrender to mere convenience.  Therefore a gathering or assembly of this kind can never be held on a Sunday in places where Mass has already been celebrated or is to be celebrated or was celebrated on the preceding Saturday evening, even if the Mass is celebrated in a different language. Nor is it right to have more than one assembly of this kind on any given Sunday.
22. Any confusion between this kind of assembly and a eucharistic celebration must be carefully avoided. Assemblies of this kind should not take away but rather increase the desire of the faithful to take part in the celebration of the eucharist, and should make them more eager to be present at the celebration of the eucharist.
23. The faithful are to understand that the eucharistic sacrifice cannot take place without a priest and that the eucharistic communion which they may receive in this kind of assembly is closely connected with the sacrifice of the Mass. On that basis the faithful can be shown how necessary it is to pray that God will "give the Church more priests and keep them faithful in their love and service." 
24. It belongs to the diocesan bishop, after hearing the council of presbyters, to decide whether Sunday assemblies without the celebration of the eucharist should be held on a regular basis in his diocese. It belongs also to the bishop, after considering the place and persons involved, to set out both general and particular norms for such celebrations. These assemblies are therefore to be conducted only in virtue of their convocation by the bishop and only under the pastoral ministry of the pastor.
25. "No Christian community is ever built up unless it has its roots and center in the eucharistic liturgy."  Therefore before the bishop decides on having Sunday assemblies without celebration of the eucharist, the following in addition to the status of parishes (see no. 5) should be considered: the possibility of recourse to priests, even religious priests, who are not directly assigned to the care of souls and the frequency of Masses in the various parishes and churches.  The preeminence of the celebration of the eucharist, particularly on Sunday, over other pastoral activities is to be respected.
26. Either personally or through his representatives the bishop will, by an appropriate catechesis, instruct the diocesan community on the causes requiring provision of these celebrations, pointing out the seriousness of the issue and urging the community's support and cooperation. The bishop is to appoint a delegate or a special committee to see to it that these people receive the necessary instruction. But the bishop's concern is always to be that several times a year the faithful involved have the opportunity to participate in the celebration of the eucharist.
27. It is the duty of the pastor to inform the bishop about the oopportunenessof such celebrations in his territory, to prepare the faithful for them, to visit them during the week, and at a convenient time to celebrate the sacraments for them, particularly the sacrament of penance. In this way the communities involved will come to realize that their assembly on Sunday is not an assembly "without a priest," but an assembly "in the absence of a priest," or, better still, an assembly "in expectation of a priest."
28. When Mass cannot be celebrated, the pastor is to ensure that holy communion be given. He is also to see to it that there is a celebration of the eucharist in due time in each community. The consecrated hosts are to be renewed often and kept in a safe place.
29. As the primary assistants of priests, deacons are called in a special way to lead these Sunday assemblies. Since the deacon has been ordained for the nurture and increase of the people of God, it belongs to him to lead the prayers, to proclaim the gospel, to preach the homily, and to give communion. 
30. In the absence of both a priest and a deacon, the pastor is to appoint laypersons, who are to be entrusted with the care of these celebrations, namely, with leading the prayers, with the ministry of the word, and with giving holy ccommunion
Those to be chosen first by the pastor are readers and acolytes who have been duly instituted for the service of the altar and of the word of God. If there are no such instituted ministers available, other laypersons, both men and women, may be appointed; they can carry out this responsibility in virtue of their baptism and confirmation.  Such persons are to be chosen in view of the consistency of their way of life with the Gospel and in the expectation of their being acceptable to the community of the faithful. Appointment is usually to be for a definite time and is to be made known publicly to the community. It is fitting that there be a celebration in which prayers are offered to God on behalf of those appointed. 
The pastor is to see to the suitable and continuous instruction of these laypersons and to prepare with them worthy celebrations (see Chapter III).
31. The laypersons appointed should regard the office entrusted to them not so much as an honor but as a responsibility and above all as a service to their brothers and sisters under the authority of the pastor. For theirs is not a proper office but a suppletory office, since they exercise it "where the need of the Church suggests in the absence of ministers." 
Those who are appointed to such an office "should do all of, but only, those parts which pertain to that office."  They should carry out their office with sincere devotion and the decorum demanded by such a responsibility and rightly expected of them by God's people. 
32. When on a Sunday a celebration of the word of God along with the giving of holy communion is not possible, the faithful are strongly urged to devote themselves to prayer "for a suitable time either individually or with the family or, iff possible, with a group of families."  In these circumstances the telecast of liturgical services can provide useful assistance.
33. Particularly to be kept in mind is the possibility of celebrating some part of the liturgy of the hours, for example, morning prayer or evening prayer, during which the Sunday readings of the current year can be inserted. For "when the people are invited to the liturgy of the hours and come together in unity of heart and voice, they show forth the Church in its celebration of the mystery of Christ."  At the end of such a celebration communion may be given (see no. 46).
34. "The grace of the Redeemer is not lacking for individual members of the faithful or entire communities that, because of persecution or a lack of priests, are deprived of celebration of the eucharist for a short time or even for a long period. They can be moved by a deep desire for the sacrament and be united in prayer with the whole Church. Then when they call upon the Lord and raise their minds and hearts to him, through the power of the Holy Spirit they enter into communion with Christ and with the Church, his living body . . . and therefore they receive the fruits of the eucharist."