From "Ceremonies of the Modern Roman Rite: The Eucharist and the Liturgy of the Hours: a Manual for Clergy and All Involved in Liturgical Ministries"
201. There are two bows in the modern Roman Rite: the bow of the body, or deep bow, and the bow of the head.
202. A bow of the body is made to the altar when the Blessed Sacrament is not on or behind it, to the celebrant, before and after incensation and when it is specified in various rites. It is always made to the bishop on approaching before leaving him and when passing in front of him during ceremonies. This bow should be gracious and unhurried. The body inclines forward from the waist, so that the hands could touch the knees, but they are kept joined as usual.
203. A bow of the head is made at the mention aloud of the three Divine Persons (during the first part of the Glory be to the Father"), at the holy names of Jesus, Mary and of the saint whose honor the liturgy is being celebrated. In pratcice, the shoulders incline slightly during this bow. When naming Our Lady of the saint of the day, it may be made more moderately than at the name of Our Lord, when these names all occur in the same test, as in the first Eucharistic Prayer. A slight bow also expresses mutual respect and gratitude before and after receiving an object or being assisted in some way during a ceremony. [Emphasis mine - Pedro]
It is really amazing how some so called experts in Liturgy who possess these diplomas from San Beda and Paul VI Institute cannot even the simple bow of the head at the mention of the name of the Lord and the Lady in the Liturgy.
Makes you wonder what is the purpose of all those intelligence really is all about?
Do we need to be schooled to show respect to the Lord? Do we need the academic degree for that?
Now here is the million dollar question, so many millions they already transferred it to secret bank accounts in Canada and Switzerland. Right Manong Jojo?
"DO YOU STILL SEE PRIESTS, BISHOPS AND ALL LAY PARTICIPANTS IN THE SANCTUARY BOWING THEIR HEADS AT THE MENTION OF THE HOLY NAME?"
Legislation or no legislation, rubric or no rubric, decorum calls for it. You don't need a gun pointed at you before you show respect.
The Lord deserves it.
So give it Him.