For each book, the shelfmark (or call number) under which it is located in the reading room or at another location is given in the catalog.
The shelfmarks begin either with the abbreviated name of the discipline - e.g. Germ, Rom - or with two capital letters that stand for parts of a discipline / subject (main group).
This is followed by a three-digit number or combination of letters and numbers (fine group), and a further numeric or alphanumeric character string (consecutive numbering of the title within the fine group).
For example: GC 370.033
GC Philosophy of language (systematic main group)
370 Logical empiricism (systematic fine group)
033 The philosophy of Rudolf Carnap (consecutive numbering of the title within the systematic fine group)
The systematic main and fine groups express the affiliation of a work to a specific subject area, which is why a thematic literature search in the catalog is possible with the corresponding letter-number combinations (enter, in our example, " GC 370* " in the field "Call Number" of the advanced search of the Catalog plus).