As explained by Adoremus Bulletin1
Norms of the Institutio Generalis Missalis Romani [liturgical instructions in the new Roman Missal] concerning the postures of the congregation during the celebration of Mass, and proposed amendments approved by the US bishops June 15, 2001, for submission to the Holy See for necessary recognitio (approval).
In this document, we first see a review of the universal norm first, followed by what was submitted after the USCCB approval. I have emphasized in bold what pertains to our discussion.
Institutio Generalis Missalis Romani
160. The priest then takes the paten or a vessel and goes to the communicants, who, as a rule, approach in a procession.
The faithful are not permitted to take up the consecrated Bread or the sacred Chalice themselves, and still less hand them on to one another. The faithful may communicate either standing or kneeling, as established by the Conference of Bishops. However, when they communicate standing, it is recommended that they make an appropriate gesture of reverence, to be laid down in the same norms, before receiving the Sacrament.
Proposed American Adaptation of IGMR §160
160. Distribution of Holy Communion
The faithful come forward in procession to receive Holy Communion. The posture for the reception of Holy Communion in the dioceses of the United States is standing. Each communicant bows his or her head before the sacrament as a gesture of reverence and receives Holy Communion from the minister. The consecrated Host may be received either on the tongue or in the hand at the discretion of each communicant. When Holy Communion is received under both kinds, the sign of reverence is made before receiving both the Body and the Blood of Christ.
Note that the universal norm says that Conference of Bishops determines whether the American norm will be for people to kneel or to stand. This was a fiercely debated point, and still is, in some Catholic forums. But, only the Church can interpret the "mind of the Church", which was done in the October 2001 letter we reviewed yesterday by Cardinal Medina Estevez in what is labeled "Part 3". In short, the Conference of Bishops can say that the norm is standing in the US, but as we see in later communications, they may not prohibit kneeling.
Just as a further comparison, and going back to our introductory post, compare the current US adaptation of GIRM 160 to the one directly above that was submitted.
160. The priest then takes the paten or ciborium and goes to the communicants, who, as a rule, approach in a procession.
The faithful are not permitted to take the consecrated bread or the sacred chalice by themselves and, still less, to hand them from one to another. The norm for reception of Holy Communion in the dioceses of the United States is standing. Communicants should not be denied Holy Communion because they kneel. Rather, such instances should be addressed pastorally, by providing the faithful with proper catechesis on the reasons for this norm.
 Online Edition - Vol. VII, No. 5-6: July-August 2001
In my next post, we'll look at more communications from the Vatican on GIRM 160.
Part 1: GIRM 160 (Introductory Post)
Part 2: Holy See clarifies GIRM 160 in November of 2000
Part 2.5: US Adapations to GIRM Approved for Submission (this post)
Part 3: Holy See Responds to US Adapations with Suggestions
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