The Our Sunday Visitors Catholic Encyclopedia (p. 815) states:
Privileged Alter . Term used in the 1917 Code of Canon Law (Canons 916-918) to describe
an altar where a plenary indulgence can be gained for a soul in purgatory by the fact that a Mass is offered for that intention
at that altar. Privileged altars were suppressed with the publication of Indulgentium Doctrina, of Pope Paul VI, on indulgences (1967), norm 20.
Norm 20 reads:
n.20—Holy Mother Church, extremely solicitous for the
faithful departed, has decided that suffrages can be applied to them to the widest possible extent at any Sacrifice of the
Mass whatsoever, abolishing all special privileges in this regard.
From the Catholic Encyclopedia (1912)
XIII. The Indulgence of the Privileged Altar132
1. The indulgence of the "privileged altar" means that to a Mass celebrated for a dead person
(i) at an altar to which the privilege has been attached, or (ii) by a priest who has received the privilege personally, the
Church attaches a plenary indulgence in favour of this deceased person.132
2. When the Church grants an indulgence in favour of a dead person; (who is no longer within its jurisdiction
on earth), it does so, not as an act of jurisdiction, as in the case of an indulgence for the living, but by Way of suffrage133 i.e., it offers to God the indulgence,134 and prays him to
accept it on behalf of the soul in question. To what extent God does actually accept this offering from the treasury
of indulgences on behalf of a dead person, and apply it to the remission of the temporal punishment owed to this person,
is unknown; it depends on the divine Will.
Accordingly, "by the indulgence attached to a privileged altar is understood—if we regard the intention of the Church135
and the the power of the keys—a plenary indulgence, which at once the soul from all the pains of purgatory; but if we
regard the effect of the application, it is to be understood as a plenary indulgence, the extent of whose effect (cujus
mensura) corresponds to the good pleasure and acceptance of divine mercy.136 As the acceptance of the indulgence
in full by God is not infallibly certain, it is permitted and a common practice to gain as far as may be possible, more than
one plenary indulgence for the soul of a deceased person.
The indulgence of the privileged altar differs from other plenary indulgences applied for the dead in that its effect is
more certain for (a) it is united to the offering of the Mass for the dead person, and so is rendered more efficacious,
since the Mass greatly helps in removing obstacles that prevent an indulgence from having its full effect, (6) there are no
conditions for the gaining of the indulgence, except the offering of the Mass.
The indulgence of the privileged altar is either (a) local, i.e., attached, permanently or otherwise, to an altar,137
so that any priest who celebrates on that altar may gain the indulgence, or (b) personal, i.e., a special favour granted
by the Holy See to an individual priest (permanently or temporarily), so that wherever138 he says Mass, he may gain the indulgence, whether the altar on which he celebrates be privileged
or not. Thus, e.g., all cardinals and bishops have the privilege personally,
and in perpetuity.139
The Holy See often grants the privilege for a place or to a person. In virtue of the Code of Canon
Law a bishop (and other religious superiors),140 may appoint and declare one altar permanently and daily "privileged,"
in public churches (provided there is not one already there) -but not in oratories, unless they are united to a parish church
or are chapels-of-ease.
7. On All Souls' Day, and on each day until November 9 (inclusive) all Masses enjoy the privilege of
the plenary indulgence, as if they had been celebrated at a privileged altar (but the indulgence must be applied to one
particular soul); and all the altars of a church are privileged on the days on which the Forty Hours' Prayer takes place therein.141
8. For Masses celebrated at a privileged altar, it is not lawful to demand — on the ground
of the privilege — a larger offering than would be given for a Mass at a nonprivileged altar.142
Conditions for Gaining the Indulgence
9. The general143 conditions laid down for the
gaining of the indulgence are:
a) The Mass must be applied — not necessarily exclusively144
— for the soul for whom the indulgence is desired and is gained;
b) The indulgence may be applied to only one soul
at a time (even though the Mass may be offered for more than one or even for all the faithful departed).145
If, therefore. Mass be offered for one dead person, by that fact the indulgence is applied (granted
that the Mass is celebrated on an altar which is privileged for that day, or by a priest who has the personal privilege), and
no special express application of it is necessary;146 but if Mass be offered for many dead persons, or for all
the souls in purgatory, it is I necessary to determine one person to whom the indulgence is to be applied.147
10. When it is desired to gain the indulgence, it is forbidden to offer
the Mass for the living (see § 9, a, supra), or even for the living and the dead. It may be offered for the dead only.148
To gain the indulgence it is not necessary that a requiem Mass be celebrated, even if the rubrics allow it on the occasion
— it suffices to offer any Mass that the rubrics permit.149 Nor is it necessary to add a prayer for the deceased person,
when the rubrics allow this (p. 114). Naturally, it is becoming to offer a requiem Mass, or add the special prayer, when this
is permitted and opportune.150
If a priest accepts an honorarium to say Mass at a privileged altar, he is bound
to do so (naturally, if he has the personal privilege he may make use of this). It will not do to substitute for the Mass
at a privileged altar, the gaining of a plenary indulgence for the dead person by some other means151 (e.g., by
making the Way of the Cross). If a priest, through inculpable error or because he is prevented by a grave cause,
does not say the Mass on a privileged altar,152 or inculpably errs in the application of the Mass (cf. §
9, supra), he need not repeat the Mass nor return the stipend given for its application.153 He is bound,
however, to gain another plenary indulgence for the deceased person, for whom he said the Mass and, if he had received a greater
stipend than the usual one (because of the condition added to the contract, i.e., that the Mass be celebrated on a privileged
altar), he is bound to restore the extra amount.154
132 This question is not a rubrical one, but it is useful
to deal with it in connection with requiem Masses.
133 I. e., intercessory prayer.
(Cf. C.J.C. 911).
134 In the case of a plenary indulgence it sets aside from the treasury of the Church
and offers to God whatever is necessary to fully remit all the temporal punishment which is due for sin forgiven, in the particular
135 Mens concedentis [indulgentiam]."
136 II., 283 (1840).
137 The altar need not be a "fixed"
one in the liturgical meaning of the term (see C.J. C. 197, § 1), but must be fixed in the sense of being a permanent structure,
and not merely a portable altar or altar stone. It is to the entire structure (a fixed altar in the liturgical sense; or a
permanent structure, having laid on its table an altar stone, and erected in honour of some mystery or saint) that the indulgence
is attached (S.C.I., D. 334; and July 18, 1902). If the altar be moved to another spot in the same church or be replaced by
a new altar, the indulgence is not lost, provided the new altar has the same title that the old one had (S.C.I., 317, 334).
138 Even on a portable altar.
239, §1 (No. 10); 349, §1,
140 See C J C. 916.
141 CJ.C. 917;
S. Penitentiary, October 31, 1934. The privilege holds even if the | Exposition is interrupted at night, when the Ordinary
of the place decides that the Exposition in the form fixed by the Clementine Instruction is not possible. (Preces et.
Pia Opera , n. 169).
142 C.J.C. 918, §2.
143 There may be other
special conditions laid down in the concession of the privilege, in particular cases, and they must, of course, be observed.
144 The Mass may be offered
for several dead persons, but the indulgence may be gained for one of them only (S.C.I., December 19, 1885; August
145 S.C.I., December
19, 1885; S. Penitentiary, July 6, 1917 (No. 3).
146 In such a case it
is not necessary that either the celebrant or the donor of the Mass offering should intend to apply the privilege (S.C.I.,
D. 366; Holy Office, June 17, 1915).
147 It is not necessary
to know this person, e.g., the indulgence may be applied to the most abandoned soul in purgatory or to the soul whom
God wishes to liberate first.
148 S.C.I., January 23,
149 Holy Office, February 20, 1913.
150 Ibid. (Cum licet ad decet) and see p. 53.
151 S. C. I., May 2, 1852 (No. 357).
152 And at the time when it, or he, has the privilege, if this be limited
to certain days.
153 As he would be bound to do in the case of culpable error about the indulgence.
154 This is the ordinary teaching of moral theologians.
Cf. also S. C. I.
D. 3393, 3572 and see p. 100.