From the shelfmark, you can recognise the location of a book or journal all the way to its position on the shelf and as well its classification to a certain subject.

Logo UB

Composition of a book shelfmark:

Location (1 letter, 2 digits) + position in the system (3 or 4 letters) + running number

Example: E31 XCB 2640(8)
E31 location; here: Essen campus, MNT Library, borrowable
XCB position (= notation) in the classification scheme; here: Civil Engineering, Structural Engineering, Building protection
2640 running number within the position in the system; in the classification of books, letters occur before numbers
Example: D11 IGJ 1035_d
D11 location; here: Duisburg campus, LK Library, 3.5th floor, borrowable
IGJ position (= notation) in the classification scheme; here: Education, General Didactics, School films
1035 running number within the position in the system; in the classification of books, letters occur before numbers
Possible additions:
Numbers in brackets, e.g (3)     edition; here: third edition
Hyphen and number, e.g -2 volume designation; here: 2nd volume of a multi-volume work
Plus sign and number, e.g +5 copy enumeration; here 6th identical copy of a book

Composition of a journal shelfmark:

Location (1 letter, 2 digits) /subject group (2 digits) + letter + running number

Example: E30/67 Z 105
E30 location; here: Essen campus, MNT Library
/67 subject group; here: Physics
Z here: journal (A and B stand for journals on microforms)
105  running number within the subject group
Example: D00/52 Z 33
D00 location; here: Duisburg campus, LK Library
/52 subject group; here: Law
Z here: journal
(up to 1980 use the letters A - Z from the journal title;
in case of EDZ journals use the letters A - X from the classification system)
33 running number within the subject group