The first question that arises is that of whether a "sign of reverence" is appropriate as you approach to receive the Eucharist. Should we not make a sign of adoration? From a catechetical point of view, the first thing is to be clear in our own minds of the difference between a sign of reverence and a sign of adoration, and, then, to be clear about what we say in parishes about this difference. We might show reverence towards holy objects - a rosary, a crucifix, statues and perhaps particularly within the Church building the altar on which the Eucharist is celebrated. But adoration is given only to the persons of the Trinity, to God. And so we adore the Holy Eucharist, the true Body and Blood of the Lord who reveals to us the Trinity.
The second question that arises is the inconsistency of our practice, both in the strictly Liturgical and in the devotional life of our parishes. The rubrics for the celebration of Mass expect a genuflection towards the tabernacle by the ministers at the start and end of Mass only, and by the priest twice at the Consecration and again just before Communion - so what to do if we pass before the tabernacle at another time during the course of the celebration? So, approaching the altar on which are present the Body and Blood of the Lord, the extraordinary minister ... bows to the altar? bows towards the Sacred species? Which is it that is actually taking place? Is the extraordinary minister reverencing the altar or adoring the Body and Blood of the Lord? And that inconsistency of practice extends to times outside of the Liturgy itself, particularly where the Eucharist is reserved in a tabernacle that is not within the main sanctuary of the Church and where the idea of genuflection almost completely disappears.
Particularly since 2005, when Pope Benedict's catechesis on adoration at World Youth Day struck me as being a wonderful teaching about the nature of genuflection as an act of adoration, I have tried to make of genuflection the two-fold act of adoration of which Pope Benedict spoke: a going down before the God who is our creator and who is so much greater than we are, and an act of union/communion with God. This two-fold movement abolishes any artificial contrast between a so-called "dynamic" understanding of the Eucharist manifested in receiving the sacred species and a so-called "static" understanding manifested in adoration outside of the celebration of Mass. This determines that the act that it is most appropriate to make towards the Eucharistic species and towards the tabernacle is a genuflection, as an act of adoration.
I like to illustrate this new step urged upon us by the Last Supper by drawing out the different nuances of the word "adoration" in Greek and in Latin. The Greek word is proskynesis. It refers to the gesture of submission, the recognition of God as our true measure, supplying the norm that we choose to follow. It means that freedom is not simply about enjoying life in total autonomy, but rather about living by the measure of truth and goodness, so that we ourselves can become true and good. This gesture is necessary even if initially our yearning for freedom makes us inclined to resist it.
We can only fully accept it when we take the second step that the Last Supper proposes to us. The Latin word for adoration is ad-oratio - mouth to mouth contact, a kiss, an embrace, and hence, ultimately love. Submission becomes union, because he to whom we submit is Love. In this way submission acquires a meaning, because it does not impose anything on us from the outside, but liberates us deep within.
[Within the heritage of the Church there is a style of bow that can also be conceived as an act of adoration - the "profound bow" - but in the usual parish context of England and Wales this would not be the normal act of adoration (which is the genuflection). The "profound bow" is made from the waist, and brings the upper body horizontal - and I have occasionally seen this from a person who for reasons of health is unable to genuflect.]
With the exception indicated in parentheses, the bow is then a sign of reverence, and not a sign of adoration.
My first appeal would therefore be for a consistency in our use of language - we adore the Eucharistic species, and we reverence other sacred objects and, sometimes, persons. We should be asked for a sign of adoration as we approach to receive Communion, and, in the normal understanding of England and Wales, that would be a genuflection; and we should be asked to show reverence towards, for example, the altar in Church, the normal sign of which would be a bow.
And my second appeal would be for a corresponding consistency in practice, both during the celebration of the Liturgy itself and at times outside such celebration. This means always genuflecting in the presence of the Eucharistic species, and not doing anything that makes it appear that a bow towards the Eucharistic species is correct practice.
The outcome might be some considerably less confused parishioners ....
[Postscript: There are, I realise since first publishing this post, one or two situations where the custom is to genuflect, without that genuflection being an act of adoration - but they are situations where the genuflection is associated with the words at that time being said. Within the Liturgy, I think of the genuflection on Christmas Day and on the Solemnity of the Annunciation during the recitation of the creed. In devotional life, I think of the genuflection during the praying of the Angelus. To really get this, the dear person in the pew does need to be aware of the difference between an act of reverence and an act of adoration.]