544 abbreviations
A.A.Augustiniani Assumptionis (Assumptionists)
A.B.Artium Baccalaureus ("Bachelor of Arts")
Ab.Abbas ("Abbot")
A.B.A.Antoniani Benedictini Armeni (Mechitarists)
Abs.Absens ("Absent")
Absoluo.Absolutio ("Absolution")
A.C.Auditor Camerae (Auditor of the Papal Treasury)
ACAnte Christum ("Before Christ")
ACNAnte Christum Natum ("Before the Birth of Christ")
A.D.Anno Domini ("Year of Our Lord")
a.d.ante diem ("The day before")
A.D.Ante Diem (e.g. in the phrase, "Ante Diem VI [or Sextum] Kal. Apriles", is equivalent to the sixth day before the Calends of April, counting both the Calends and the day intended to be indicated); or Anima Dulcis ("Sweet Soul")
Adm. Rev.Admodum Reverendus ("Very Reverend")
Adv.Adventus ("Advent")
al.alii, alibi, alias ("others", "elsewhere", "otherwise")
Alb.Albus ("White" Breviary)
Alr.Aliter ("Otherwise")
A.M.Anno Mundi ("in the year of the world")
A.M.Artium Magister ("Master of Arts")
A.M.D.G.Ad Majorem Dei Gloriam ("For the greater glory of God")
An.Annus ("Year")
Ana, Ant.Antiphon
Ann.Anni ("Years")
Apost.Apostolus ("Apostle")
Appatis.Approbatis ("Having been approved")
Applica.Apostolica ("Apostolic")
Ap. Sed.Apostolica Sedes ("Apostolic See")
Ap. Sed. Leg.Apostolicae Sedis Legatus ("Legate of the Apostolic See")
A.Q.I.C.Anima Quiescat In Christo ("May his [or her] Soul Repose in Christ")
Archid.Archidiaconus ("Archdeacon")
Archiep.Archiepiscopus ("Archbishop")
Archiepus.Archiepiscopus ("Archbishop")
Archiprb.Archipresbyter ("Archpriest")
A.R.S.Anno Reparatae Salutis ("In the year of Our Redemption")
A.U.Alma Urbs ("Beloved City" i.e., Rome)
Aucte.Auctoritate ("By the Authority")
Authen.Authentica ("Authentic" e.g. letters)
Aux.Auxilium, Auxilio ("Help", "With the help of")
B., BMT.Bene Merenti ("To the Well-Deserving")
B.A.Baccalaureus Artium ("Bachelor of Arts")
B. BB.Beatus, Beati ("Blessed")
B.C.Before Christ
B.C.L.Baccalaureus Civilis [or Canonicae] Legis ("Bachelor of Civil [or Canon] Law")
B.D.Bachelor of Divinity
Ben.Benedictio ("Blessing")
Benevol.Benevolentia ("Benevolence")
B.F.Bona Fide ("In Good Faith")
B.F.Bonae Feminae ("To the Good Woman")
B.I.C.Bibas [for Vivas] In Christo ("May you Live In Christ")