The library holdings published since 1982 are indexed by discipline or field of study. The scheme which is used is the TUM Classification System. It consists of 52 main classes with up to 999 sub-classes. The system is (not strictly) hierarchical.
The classification system plays two roles:
- Firstly, it facilitates subject access – in addition to verbal indexing with subject headings – by allowing the user to find out which items the library has on a certain subject.
- Secondly, it provides information for shelf location in the reading rooms.
The main classes and sub-classes of the classification system are represented by so-called notations, a system of characters and numbers.
A three character mnemonic letter code identifies the main classes, a three digit numerical code the sub-classes, e.g. ELT 515f.
This example refers to the sub-class Signals Theory and Signals Processing. The key letter f denotes that this is a monograph.
You will find notations:
- in shelfmarks: for the shelving of library items in the reading rooms
- in bibliographic data: for subject indexing, which you can use for your search in the online catalogue.