From the letter Sub Catholicae to the Bishop of Tusculum, of the Legation of the Apostolic See among the Greeks, March 6, 1254:
And so concerning these matters our deliberation has resulted thus, that Greeks of the same kingdom in the anointings, which are made with respect to baptism, should hold to and observe the custom of the Roman Church. But the rite or custom which they are said to have, of anointing completely the bodies of those to be baptized may be tolerated, if it cannot be given up or be removed without scandal, since, whether or not it be done, it makes no great difference with regard to the efficacy or effect of baptism. Also it makes no difference whether they baptize in cold or in hot water, since they are said to affirm that baptism has equal power and effect in each.
Moreover, let bishops alone mark the baptized on the forehead with chrism, because this anointing is not to be given except by bishops, since the apostles alone, whose places the bishops take, are read to have imparted the Holy Spirit by the imposition of the hand, which confirmation, or the anointing of the forehead represents. Also all bishops individually in their own churches on the day of the Lord’s Supper can, according to the form of the Church, prepare chrism from balsam and olive oil. For the gift of the Holy Spirit is given in the anointing with chrism. And particularly the dove, which signifies the Spirit Himself, is read to have brought the olive branch to the ark. But if the Greeks should wish rather to preserve their own ancient rite in this, namely, that the patriarch together with the archbishops and bishops, his suffragans and the archbishops with their suffragans, prepare chrism at the same time, let them be tolerated in such a custom of theirs.
Furthermore in the application of water, whether cold or hot or tepid, in the sacrifice of the altar, let the Greeks follow their own custom if they wish, as long as they believe and declare that, when the form of the canon has been preserved, it is accomplished equally by each (kind of water). But let them not preserve the Eucharist consecrated on the day of the Lord’s Supper for a year on the pretext of the sick, that with it they may obviously communicate themselves. It may be permitted them, however, in behalf of the sick themselves, to consecrate the body of Christ and to preserve it for fifteen days, but not for a longer period of time, lest through its long preservation, perchance by a change in the species, it be rendered less suitable to receive, although the truth and its efficacy always remain entirely the same, and never by any length of time or the mutability of time do they grow weak. But in the celebration of solemn and other Masses, and concerning the hour of celebrating these, as long as in the preparation and in the consecration they observe the form of words expressed and handed down by the Lord, and (as long as) in celebrating they do not pass the ninth hour, let them be permitted to follow their own custom.
From the decrees of the Ecumenical Council of Florence, Session 6, 6 July 1439:
Also, the body of Christ is truly confected in both unleavened and leavened wheat bread, and priests should confect the body of Christ in either, that is, each priest according to the custom of his western or eastern church. Also, if truly penitent people die in the love of God before they have made satisfaction for acts and omissions by worthy fruits of repentance, their souls are cleansed after death by cleansing pains; and the suffrages of the living faithful avail them in giving relief from such pains, that is, sacrifices of masses, prayers, almsgiving and other acts of devotion which have been customarily performed by some of the faithful for others of the faithful in accordance with the church’s ordinances.