Could you perhaps explain this further? I have not seen this word “prescription” used before in a canonical sense as you do. And can you cite this reference? I do not think the bishops here ever speak in such a legalistic way, when so many of them allow a variety of signs of reverence to be given.
Does declaring something as a “norm” mean it is morally required?
Instruction Redemptionis Sacramentum states the following:
[90.] “The faithful should receive Communion kneeling or standing, as the Conference of Bishops will have determined”, with its acts having received the recognitio of the Apostolic See. “However, if they receive Communion standing,* it is recommended that they give due reverence before the reception of the Sacrament**, as set forth in the same norms”.*
And in the General Instruction of the Roman Missal:
*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.
When receiving Holy Communion,
the communicant bows his or her head before the Sacrament as a gesture of reverence and receives the Body of the Lord 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 also made before receiving the Precious Blood.*
GIRM 160 is part of the adaptations and will differ from territory to territory. What I quoted is from the adaptations for the US. You can always refer to GIRM 160 of every territory/country to see what the norms are for that country.
I use the word “prescription” because its a strong recommendation. Not a forceful command but at the same time not merely a suggestion.