From its very start, the Library collects books, series documents, musical documents, maps, carvings, placards, small prints and manuscripts. At present we manage 560.000 documents altogether on stacks 6,789 running meter long.
In our Special Collections we preserve 146 incunables, 1,600 early Hungarian books (published prior to 1711) and 2,500 books printed prior to 1,600.
The classification rules of our Library were established in the 1870s and used until 1951. Subject groups listed and named according to the alphabet preserved and enlarged the principles already in use in the 17-18th centuries. Subject groups were catalogued in written registers, books had their own papers, that were in use until the card catalogues have appeared.
A: universal knowledge (bibliographies, general works and omnibus volumes)
B: practical theology (homiletics, liturgy, religious education, counselling, mission, etc.)
C: systematic theology (dogmatics, ethics, confessions, philosophy of religion)
D: church history
E: exegetics (biblical studies, isagogics, hermeneutics, bibliology, history of biblical times, concordances)
F: theology in general (history of religions, church life, ecumene)
G: classical and eastern languages and linguistics
H: Hungarian litarture (history of literature, linguistics, belles lettres)
I: history of Hungary
K. history of the world, history of art
L: Hungarian law
M: universal law
N: humanities (philosophy, psychology)
O: natural sciences (mathematics, physics, chemistry, etc.)
P: biology, economy (agriculture)
Q: health science
T: foreign literature (foreign belles lettres, history of literature, linguistics, grammar, etc)