Originally Posted by Cavaille-Coll
According to the Catechism of the Catholic Church (1183), the tabernacle should be located "in churches in a most worthy place with the greatest honor." I don't see how placing the tabernacle in a small chapel in the back of the church meets this mandate.
Good point. And also GIRM 2010:
The Place for the Reservation of the Most Holy Eucharist
314. In accordance with the structure of each church and legitimate local customs, the Most Blessed Sacrament should be reserved in a tabernacle in a part of the church that is truly noble, prominent, conspicuous, worthily decorated, and suitable for prayer.
The tabernacle should usually be the only one, be irremovable, be made of solid and inviolable material that is not transparent, and be locked in such a way that the danger of profanation is prevented to the greatest extent possible.
Moreover, it is appropriate that before it is put into liturgical use, the tabernacle be blessed according to the rite described in the Roman Ritual.
315. It is more appropriate as a sign that on an altar on which Mass is celebrated there not be a tabernacle in which the Most Holy Eucharist is reserved.
Consequently, it is preferable that the tabernacle be located, according to the judgment of the Diocesan Bishop:
a) either in the sanctuary, apart from the altar of celebration, in a appropriate form and place, not excluding its being positioned on an old altar no longer used for celebration (cf. no. 303);
b) or even in some chapel suitable for the private adoration and prayer of the faithful
and organically connected to the church and readily noticeable by the Christian faithful.
316. In accordance with traditional custom, near the tabernacle a special lamp, fueled by oil or wax, should shine permanently to indicate the presence of Christ and honor it.
317. In no way should any of the other things be forgotten which are prescribed by law concerning the reservation of the Most Holy Eucharist.
and Canon Law 1983:
The Code of Canon Law codified these developments in 1983.
CIC Canon 938
º1. The Most Holy Eucharist is to be reserved regularly in only one tabernacle of a church or oratory.
º2. The tabernacle in which the Most Holy Eucharist is reserved should be placed in a part of the church that is prominent, conspicuous, beautifully decorated, and suitable for prayer.
º3. The tabernacle in which the Eucharist is regularly reserved is to be immovable, made of solid and opaque material, and locked so that the danger of profanation may be entirely avoided.
º4. For a grave cause, it is licit to reserve the Most Holy Eucharist in another safer and becoming place especially during the night.
º5. The person who has charge of the church or oratory is to see to it that the key of the tabernacle in which the Most Holy Eucharist is reserved is safeguarded most diligently.
But for the eastern Catholics 1990 it may vary:
CCEO Canon 714
1. In churches where public divine worship and, at least several times in a month, the Divine Liturgy is celebrated, the Divine Eucharistic is to be reserved especially for the sick, and also is to be adored with the greatest reverence by the Christian faithful, with due regard for the faithful observance of the prescriptions of the liturgical books of each Church sui iuris.
2. The reservation of the Divine Eucharist is under the vigilance and moderation of the local hierarch.