Book signature

Every book in the library has a combination of numbers and letters on the spine label. You will also find this information, called a shelfmark, when searching the catalogue.

The shelfmark provides information about

  • at which location (subject library or stacks),
  • where the book is located on the shelf,
  • whether the book can be borrowed or whether it is part of the reference collection,
  • which edition of the work it is,
  • which volume of the work it is (in the case of multi-volume works).


The following shelfmark should be used to explain what information it contains:

51 XKA 1015 (19)-1+4

51 = location code number

The location code number provides information about the borrowability of a book as well as its location.

The following applies to borrowability:

  • Holdings with odd location codes and white spine labels => lending stock
  • Holdings with even location codes and yellow spine labels => reference holdings(short loan possible)
  • Items with a location code number ending in 8 and a red spine label => absolute reference holdings (cannot be borrowed).

The following applies to the location

  • Holdings with the location codes 10/11/18/30/31/38/40/41/48/50/51/58 are in the subject libraries. The first digit does not correspond to the levels of the subject libraries.
  • Holdings with different location codes are at special locations.
51 XKA 1015 (19)-1+4

XKA = system location of the collection systematics

The system locations consist of three or four letters and range from AAA-ZZZ.

Certain groups of system locations are assigned to individual subjects and thus also to the subject libraries on the five levels.

Each combination of letters stands for a specific subject area. You will also find them at the top of the front sides of the shelves in the subject libraries. The thematically structured book arrangement means that books with related content are grouped together. Information on the individual system locations can be found in the subject classification of books and on the notice boards on the shelves of the subject libraries. The individual system locations can also be searched in the catalogue.

51 XKA 1015 (19)-1+4

1015 = Sequence number for a title within a system location.

This determines the exact location of the book on the shelf. The last digit is only a check digit and can be ignored.

51 XKA1015 (19)-1+4

(19) = edition

From the 2nd edition of a work, this is taken into account in the signature. The edition of a work with the highest edition number is the most recent in the library's collection.

51 XKA1015 (19)-1+4

-1 = volume number (for multi-volume works)

51 XKA1015 (19)-1+4

+4 = copy number (for books that are in the library more than once)

Any questions?

If you have any questions about the book arrangement and the signatures, the staff at the Information Centre and in the specialist libraries will be happy to help you.