The books of the library are organised on the shelves according to the following system.
Call numbers are composed as follows:
33-234 or ND-1567
The first two characters of the call number indicate the subject group of the book, the second part marks the numerical position within the subject group.
| 00 | Reference literature, dictionaries |
| 01, A01 | Festschriften and intellectual history |
| 01-5 | Conference proceedings |
| 02 | Periodicals |
| 03-04 | Text editions |
| 05-07 | Byzantine literature |
| 08 | Vernacular literature |
| 10-11 | Manuscript catalogues, textual tradition, codicology, papyrology |
| 14 | Diplomatics |
| 15 | Greek language |
| 17 | Metrics and music |
| 18 | Translations |
| 19 | Popular fiction on Byzantium |
| 20-21 | Theology |
| 23 | Apocrypha |
| 24 | Hagiography |
| 26 | Liturgics |
| 30-32 | History |
| 33 | Economic history, cultural history |
| 36-37 | Religious and church history |
| 38 | Monasticism |
| 39 | Chronology, bibliography and genealogy |
| 40-41 | Topography, geography and ethnography, archaeology |
| 50 | Art history |
| 53 | Icons |
| 55 | Architecture |
| 56 | Sculpture |
| 57 | Painting |
| 58 | Minor arts |
| 59 | Exhibitions, museum catalogues |
| 60 | Heraldics, numismatics and sigillography |
| 70 | Epigraphy |
| 80 | Jurisprudence |
| 85 | Canon law |
| 90 | Realia |
| 91 | Mathematics and subject disciplines |
| 92 | Medicine |
| 93 | Military science |
| 93-5 | Theses and dissertations |
| 94-97 | Offprints |
| 98 | School programs |
| 99 | Rara |
| C | Caucasica |
| PO | Patrologia Orientalis |
| ACO | Acta Conciliorum Oecumenicorum |
| MANSI | Sacrorum conciliorum nova et amplissima collectio |
| PG | Patrologia Graeca |
| AS | Acta Sanctorum |
| Restle | Donation Marcell Restle |
| X | Audiovisual media |
| NA | Modern Greek studies: Primary literature |
| NB | Modern Greek studies: Secondary literature |
| ND | Modern Greek studies: History |
| NE | Sources, archives, repertories |
| NM | Media, film, TV, music, photography |
| NL | Modern Greek language, text- and workbooks |
