Gabor Mandy

The Utilization of Old UDC Numbers

The recent trend in information searching is post-coordination that makes it possible that the user can combine the elements at the time of the search. The precondition of this is the existence of small content elements. New notations can be created relatively easily but we should also be able to make the mass of old UDC notations usable. Gabor Mandy, then a member of the Metropolitan Library of Budapest, catalogunig unit, suggested an easy method for the utilization of old (pre-2001) notations and gave a simple algorithm, in which complex notations can be broken down by a chain of small, single-purpose programs.

As an example, from the complex notation of 830-322.4 we can retrieve 830, 82-32 and 82-312.4 (German literature, short story, criminal theme). The same way, 372.851.1 can be understood as the combination of 372.8 and 511 (disciplines and number theory). The chain of programs makes sure that whatever element cannot be analysed by the actual program is passed on to the next one. The end result is the variety of elements which can be searched and combined in the post-coordinated search process.

Take this notation as an example of the computer analísis. The line to be examined contains the record ID and the complex notation.

000003358453 32(4-11)"197/198"

Cut off the record ID (this is to travel with each element and points to the document).

The complex notation is:


32 is a class (politics), it is to be saved to the file of the resolved problems, together with the record ID:

000003358453 %32

(The % sign indicates that this is just an element of the contents, not a monography on politics in general. You can argue that everything is an elements and this should not be indicated but let us assume that there are monographs about each subject and we want to note the difference.)

The rest of the notation is to be analysed:


(4-11) is a composite geographic notation that needs to be broken down:

(4) is Europe and (1-11) is east as a direction. To be saved into the file of resolved problems are:

000003358453 %(4) and

000003358453 %(1-11)

(Again, the document is not about Europe or about the eastern direction in general.)

The rest of the notation indicates the time period:


It is also to be saved:

000003358453 %"197/198"

So, in the process of the post-coordinated search these elements can be combined and the hits will point to the same document (with the 000003358453 record ID).

A further problem evolves from the simplified classification practices. Most libraries (at least in Hungary) did not indicate that a certain document is in the monography form. Another imperfection was that English literature in England was indicated by a simple 820 notation, instead of 820(42), only the English literary works outside England were given the geographical element, e.g. 820-32(73) as American novel. (The same with every national literature.)

If we want to be exact, we also should differentiate between the use of an element as the main subject of the document (such as 820-312.4 as English criminal novel) and as the type of approach (like in the case of the criminal short story, where the -312.4 element is only an analogy to indicate the subgenre).

However, taking into consideration the order of magnitude of the material to be processed and recatalogued, this last problem can be thought of less importance.

The essay in Hungarian was published in the journal Könyvtári Figyelő, with actual algorithms and programming samples.

Also, there is a webpage (in Hungarian) where you can see how the elements are derived from certain complex notations:

Könyvtári menü