V. Variations in the Divine Office
19. Pending the complete reform of the divine office, on days of class I and class II with a matins of three nocturns, recitation of any one nocturn with three psalms and three readings is permitted. The hymn Te Deum, when called for by the rubrics, comes after the third reading. In the last three days of Holy Week the pertinent rubrics of the Roman Breviary are to be followed.
20. Private recitation leaves out the absolution and blessing before the readings as well as the concluding Tu autem.
21. In lauds and vespers celebrated with a congregation, in place of the capitulum there can be a longer reading from Scripture, taken, for example, from matins or from the Mass of the day, or from a weekday lectionary, and, as circumstances suggest, a grief homily. Unless Mass immediately follows, general intercessions may be inserted before the prayer.
When there are such insertions, there need only be three psalms, chosen in this way: at lauds one of the first three, then the canticle, then the final psalm; at vespers any three of the five psalms.
22. At compline celebrated with a congregation participating the psalms can always be those of Sunday.