ChapterV-I. Offices to be Carried Out
253. In the celebration of the liturgy of the hours, as in all other liturgical services, "each one, minister or layperson, 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 liturgy." 
254. When a bishop presides, especially in the cathedral, he should be attended by his college of priests and by ministers and the people should take a full and active part. A priest or deacon should normally preside at every celebration with a congregation and ministers should also be present.
255. The priest or deacon who presides at a celebration may wear a stole over the alb or surplice; a priest may also wear a cope. On greater solemnities the wearing of the cope by many priests or of the dalmatic by many deacons is permitted.
256. It belongs to the presiding priest or deacon, at the chair, to open the celebration with the introductory verse, begin the Lord's Prayer, say the concluding prayer, greet the people, bless them, and dismiss them.
257. Either the priest or a minister may lead the intercessions.
258. In the absence of a priest or deacon, the one who presides at the office is only one among equals and does not enter the sanctuary or greet and bless the people.
259. Those who act as readers, standing in a convenient place, read either the long readings or the short readings.
260, A cantor or cantors should intone the antiphons, psalms, and other chants. With regard to the psalmody, the directions of nos. 121-125 should be followed.
261. During the gospel canticle at morning prayer and evening prayer there may be an incensation of the altar, then of the priest and congregation.
262. The choral obligation applies to the community, not to the place of celebration, which need not be a church, especially in the case of those hours that are celebrated without solemnity.
263. All taking part stand during:
a. the introduction to the office and the introductory verses of each hour;
b. the hymn;
c. the gospel canticle;
d. the intercessions, the Lord's Prayer, and the concluding prayer.
264. All sit to listen to the readings, except the gospel.
265. The assembly either sits or stands, depending on custom, while the psalms and other canticles (with their antiphons) are being said.
266. All make the sign of the cross, from forehead to breast and from left shoulder to right, at:
a. the beginning of the hours, when God, come to my assistance is being said;
b. the beginning of the gospel, the Canticles of Zechariah, of Mary, and of Simeon.
The sign of the cross is made on the mouth at the beginning of the invitatory, at Lord, open my lips.