Part II-1. Some General Norms on Structuring Celebration of the Memorial of the Lord in the Community of the Faithful
Unity of the Community Shown in the Celebration
16. In virtue of baptism "there is neither Jew nor Greek, slave nor freeman, male nor female," but all are one in Christ Jesus (See Gal 3:28). Therefore the assembly that most fully manifests the nature of the Church in the eucharist is one in which the faithful of every class, age, and condition are joined together.
Nevertheless the unity of the community, which is derived from the one bread in which all share (see 1 Cor 10:17), has a hierarchic structure. For this reason it requires that "each one, minister or lay person, who has an office to perform, should do all of, but only, those parts which pertain to that office by the nature of the rite and the principles of the liturgy." 
The best example of this is found "in the full, active participation of all God's holy people . . . in the same eucharist, in a single prayer, at one altar at which the bishop presides, surrounded by his college of priests and by his ministers." 
Avoiding the Scattering and Distracting of the Community
17. In liturgical celebrations, any breakup or distraction of the community must be avoided. Care must be taken, accordingly, not to have two liturgical celebrations going on in the same church at the same time, since this would distract the attention of the people.
Above all this must be stressed in regard to the celebration of the eucharist. Hence the scattering of the people that generally occurs when Masses are celebrated at the same time in the same church should be carefully avoided on Sundays and holy days of obligation when Mass is celebrated for the people.
The same rule should be applied as far as possible on other days as well. The best way to achieve this is concelebration, in conformity with the law, by priests who want to celebrate Mass at the same time. 
Similar precautions must be taken against the communal or choral recitation of the office, sermons, the administration of baptisms, and the celebration of marriages at the same time and in the same church as a scheduled Mass for the people is being celebrated.
Snse of the Local and Universal Community Fostered
18. In the celebration of the eucharist, a sense of community should be fostered so that all will feel united with their brothers and sisters in the communion of the local and universal Church and even in a certain way with all humanity. For in the sacrifice of the Mass Christ offers himself for the salvation of the whole world and the congregation of the faithful is the type and sign of the unity of the human family in Christ its Head. 
Welcoming Visitors into the Local Celebration of the Eucharist
19. The faithful who take part in the celebration of the eucharist outside their own parish should join in the form of the sacred services that the local community uses.
Pastors have the responsibility of providing suitable ways to assist the faithful from other regions to join with the local community. This should be of particular concern in the churches of large cities and in places where many of the faithful gather for vacations.
Where there are many visitors or expatriates of another language, pastors should provide them with the opportunity, at least occasionally, to participate in the Mass celebrated in the way customary for them. "Nevertheless steps should be taken enabling the faithful to say or to sing together in Latin those parts of the Ordinary of the Mass belonging to them." 
Carefulness About the Manner of Celebrating
20. To ensure that the celebration is conducted properly and that the faithful take an active part, the ministers should not only fulfill their role correctly according to the norms of liturgical laws, but their very bearing should communicate a sense of the sacred.
The people have the right to be nourished by the word of God proclaimed and explained. Accordingly priests are to give a homily whenever it is prescribed or seems advisable; but they are also to see to it that anything that their functions require them and the ministers to pronounce is said or sung so distinctly that the people hear it clearly, grasp its meaning, and are thus drawn to respond and participate willingly.  To this end ministers should be prepared through the right kind of training, especially in seminaries and religious houses.
Canon of the Mass
21. a. According to the provisions of the Instruction Tres abhinc annos, 4 May 1967, no. 10, in Masses celebrated with a congregation, even when not concelebrated, the priest celebrant may say the canon aloud. In sung Masses he may sing those parts of the canon that may be sung according to the Rite of Concelebration.
b. In printing the words of consecration the custom of setting them in type different from the general text should be maintained in order that they may stand out more clearly.
Radio and Television Broadcasts of Mass
22. Where, according to the intent of the Constitution on the Liturgy art. 20, the Mass is televised or broadcast, local Ordinaries should see that the prayer and participation of the faithful in attendance are not disturbed; furthermore, the celebration should be marked with such care and dignity that it is a model of celebrating the sacred mysteries according to the laws of the liturgical reform. 
Photographs during the Celebration of the Eucharist
23. Strict care should be taken to ensure that liturgical celebrations, especially of the Mass, are not disturbed by the practice of taking photographs. Where a reasonable cause for them exists, everything should be done with great restraint and according to the norms established by the local Ordinary.
Importance of the Arrangement of Churches for Well-Ordered Celebrations
24. "The church, the house of prayer, must be well cared for and suited to prayer and liturgy. There the eucharist is celebrated and reserved and the faithful gather for worship. There the presence of the Son of God, our Savior, offered on the altar of sacrifice for us, is treasured and revered as the aid and solace of the faithful." 
Pastors should understand, therefore, that the becoming arrangement of the place of worship contributes much to a right celebration and to the active participation of the faithful.
For this reason the rules and directives given in the Instruction Inter Oecumenici (nos. 90-99) should be followed regarding: the building of churches and their adaptation to the reformed liturgy; the construction and appointment of altars; the proper placement of chairs for the celebrant and ministers; the provision of a proper place for the proclamation of the readings; the arrangement of places for the faithful and the choir.
Above all, the main altar should be so placed and constructed that it always appears as a sign of Christ himself, as the place in which the sacred mysteries are carried out, and as the focal point for the gathered faithful, which demands the highest respect.
Care should be taken against destroying treasures of sacred art in the course of remodeling churches. On the judgment of the local Ordinary, after consulting experts and, when applicable, with the consent of other concerned parties, the decision may be made to relocate some of these sacred treasures in the interest of the liturgical reform. In such cases this should be done with good sense and in such a way that even in their new locations they will be set up in a manner befitting and worthy of the works themselves.
Pastors should remember that the material and design of vestments greatly contribute to the dignity of the liturgical celebrations. Vestments should be designed "for a noble beauty rather than mere sumptuous display."