Polythematic Structured Subject Heading System (PSH)

Polythematic Structured Subject Heading System (PSH) is a bilingual Czech–English controlled vocabulary of subject headings which is used for organizing and searching the documents by subject. It is developed and maintained at the National Library of Technology of Prague. PSH contains over 13 900 subject headings in its latest version PSH 4.0 and is divided into 44 thematic sections which cover the main fields of human knowledge. Each subject heading is included in a hierarchy of six (or - under special circumstances - seven) levels according to its semantic content and specificity. The whole system is a tree structure and it represents various concepts from the most general to more specific ones. There are hierarchical, associative and equivalence relations in PSH.

Search PSH

Frequently asked questions about PSH

Available Formats

PSH is available in a MARC 21 Format for Authority Data which is used for storage, maintenance and sharing PSH in library automated systems. PSH is also available in SKOS (Simple Knowledge Organization System), using RDF/XML syntax, which is suitable for the web distribution. Single subject headings can be accessed on the PSH website through URL links. Alternatively, the whole vocabulary can be downloaded in one file.


PSH/SKOS is available under the Creative Commons License CC BY 3.0 CZ (Attribution-ShareAlike 3.0 Czech Republic). That means you are free to copy, distribute, display and perform the work and make derivative works, but you also must give the original author credit and if you alter, transform, or build upon this work, you may distribute the resulting work only under a licence identical to this one.

Browse PSH

There are two main tools for browsing PSH (both developed at the National Library of Technology of Prague) - PSH Browser and PSH Manager.

PSH Browser is a tool that navigates the users through PSH from general to more specific terms. Users can also use the Search field. It is possible to display tags from PSH (metadata snippets – Dublin Core and CommonTag), which can be embedded in an HTML document to provide its semantic description in a machine-readable way.

PSH Manager, on the other hand, serves mostly to catalogers and PSH developers.

PSH is also integrated in the National Library of Technology's on-line catalogue, the website of the Czech Technical University in Prague and the STM Portal's on-line catalogue.

Suggest a New Heading

Libraries and individuals can contribute to updating PSH by suggesting new headings. Either use the  web form or email us.

Suggest a new heading

Suggest a new PSH heading in the form below.

Suggest a new heading
Please type number 42 to prove you're human.


Let’s say you have a book entitled: Telegeoinformatics: location-based computing and services (ISBN 0415369762). You know it’s about geoinformatics and geographic information systems. In the suggestion form, add the heading suggestion and/or synonym:

New PSH heading: "geoinformatics".
Synonym for the new heading (in English; optional): "geographic information systems".
ISBN or ISSN: 0415369762

Please note you don’t need to add the title of the item.

Publications & Links

PSH on the Web

Here you can see how PSH is used in practice:

  • The University of Pardubice has integrated PSH into a specialized search engine for finding scholars based on their research and development outputs.
  • The National Library of Technology has integrated PSH into its catalog.
  • The Czech Technical University in Prague also utilizes PSH.
  • The STM web portal has integrated PSH headings into its advanced search and catalog.
  • Generator of metadata in WebArchiv.
  • PSH enables document navigation/delivery by subject on the ESO web portal of the Prague Institute of Chemical Technology.



    BUSCH, Kristýna.Identifying candidates for the new subject headings based on the web behaviour of end-users [poster]. In 41st Annual LIBER Conference 2012. [cit. 2012-17-07]. Access via the NTK repository.
    BUSCH, Kristýna.Traditional library data in a non-library context: controlled vocabulary for indexing scientific interests in the profiles of academic researches [presentation]. In ELAG Conference 2012 [online]. [cit. 2012-17-07]. Access via the NTK repository.


    MYNARZ, Jindřich; KAMRÁDKOVÁ, Kateřina; KOŽUCHOVÁ, Kristýna.Polythematic Structured Subject Heading System & Creative Commons. The Grey Journal: An International Journal on Grey Literature. 2010, Vol. 6, N. 3, PP. 129-135. ISSN 1574-1796.


Version 4.0 (MARC 21)
Version 3.0 (MARC 21)

PSH is published under the licence Creative Commons CC BY 3.0 CZ (Attribution ShareAlike 3.0 Czech).

New and updated PSH headings




PSH logo

Short variant (gif) (6 kB)

Long variant (gif) (11 kB)

PSH History

1993 - Work on the subject heading system started, these activities were supported by several grants provided by the Ministry of Culture of the Czech Republic and the Ministry of Education, Youth and Sports of the Czech Republic.

1997 - PSH was distributed to all interested parties - libraries and commercial companies.

2000 - PSH Version 1.3 was distributed.

2000 - In April, the State Library of Technology (today's National Library of Technology) received financial support from the Ministry of Culture of the Czech Republic to translate PSH into the English language. PSH Version 1.4 is therefore bilingual.

2001 - PSH Version 1.4 was distributed. Based on the decision of the Ministry of Culture of the Czech Republic, the subject heading system was offered freely to public libraries, and with a fee to commercial companies. It was provided as a TXT. file in which the order of the subject headings indicated the hierarchical structure. Each row contained a subject heading in Czech and in English, both accompanied by relevant references. Modified freeware which could link Czech and English subject headings and offered search capabilities was a part of the package.

2002 - A special maintenance module for the subject heading system was commissioned by the State Library of Technology from KP-Sys (a company producing automated library systems). Revision of PSH Version 1.4. began.

2005 - PSH Version 2.0 was completed but due to a number of shortcomings it was not distributed to users.

2006 - Large-scale corrections of PSH Version 2.0 took place and a new version 2.1 was introduced.

2006 - In November, PSH in its latest version (2.1) was implemented to Aleph, an automated library system currently used at the National Library of Technology.

2009 - PSH was published in a SKOS format.

2010 - The version PSH 3.0 was released.

2013 - New version PSH 4.0 (in MARC21 format) published.

2013 - Application for automatic indexing of documents with PSH headings distributed.

Logo PSH



Editor: Stephanie Krueger Last modified: 4.4. 2017 16:04