[quote="Chatter163, post:8, topic:330722"]
The APA Handbook does not concern itself with the names of Catholic sacraments, so no citation is possible. Ditto the MLA Handbook. However, since these are not proper nouns, one does not normally capitalize them. The capitalization here is something new to the recent English translation of the missal, as none of the previous English translations included it, nor did Latin-English people's missals of old. (Needless to say, it does not appear in the Latin, either.)
I made no reference to the APA Handbook. You might want to re-read my original entry. My reference is to the AP Stylebook as in Associated Press.
I just dug out my copy of the AP (not APA) Stylebook. With reference to the AP Stylebook (not the APA Handbook):
Capitalize the proper names used for a sacramental rite that commerates the life of Jesus Christ or signifies a belief in his presence: the Lord's supper, Holy Communion, Holy Eucharist.
Lowercase the names of other sacraments: baptism, confirmation, penance (now often called the sacrament of reconciliation), matrimony, holy orders, and the sacrament of annointing of the sick (formerly extreme unction). .
Associated Press Stylebook (not the APA Handbook) page 225 (2002 edition).
I also would add that no handbook is definitive. Different organizations and professions have different rules as to what is capitalized. The style that I learned in law school ("Blue Book") is very different from the AP style that I learned as an undergrad journalism major which is very different from the MLA style that I used when writing a research paper in my English and history classes. So what might not look correct to us might be correct by the style used by the translators of the Creed.