Marriage, unlike Christian Initiation, is nearly universally observed culturally. And naturally, it predates the Judeo-Christian tradition.
57. In many places it is the marriage rite that calls for the greatest degree of adaptation so as not to be foreign to social customs. To adapt it to the customs of different regions and peoples, each episcopal conference has the “faculty to prepare its own proper marriage rite, which must always conform to the law which requires that the ordained minister or the assisting layperson, (Cf. Canons 1108 and 1112.) according to the case, must ask for and obtain the consent of the contracting parties and give them the nuptial blessing.” (SC 77, Ordo Celebrandi Matrimonium, editio typica altera, Praenotanda, 42) This proper rite must obviously bring out clearly the Christian meaning of marriage, emphasize the grace of the sacrament and underline the duties of the spouses. (SC 77)
I don’t know that there is much to comment on with this. The “faculty” rests with the national conference, not Rome and not individual bishops. The essential elements are the consent and the nuptial blessing. And of course, somewhere in its content to draw out the sacramental understanding of marriage.
Catholic Sensibility 