"Wikidata is a free linked database that can be read and edited by both humans and machines. Wikidata acts as central storage for the structured data of its Wikimedia sister projects including Wikipedia, Wikivoyage, Wikisource, and others. Wikidata also provides support to many other sites and services beyond just Wikimedia projects! The content of Wikidata is available under a free license, exported using standard formats, and can be interlinked to other open data sets on the linked data web."

ETIM Classification

"Product classification is simply a logical, unambiguous classification (taxonomy) of products in different product classes (categories), designed so that anyone within the sector can communicate about those products without misunderstandings. The ETIM model gives a listing of the most important technical characteristics of each product class to describe and find the products. Each class has several synonyms, thereby finding the right product is much easier for everyone! (...) Uniform product classification in itself is not a final product as it is.

CERL Thesaurus

"The CERL Thesaurus File is a unique facility developed to address the particularly European issue that place name and personal names in Europe varied from country to country in the period of hand press printing (1450 - c. 1830). As such, it is an essential research tool for scholars and researchers of the period. The CERL Thesaurus file contains forms of imprint places, imprint names, personal names and corporate names as found in material printed before the middle of the nineteenth century - including variant spellings, forms in Latin and other languages, and fictitious names.

Schema voor de Indeling van de Systematische Catalogus in Openbare Bibliotheken

"SISO is een numeriek systeem dat de informatieve media in uw bibliotheek naar onderwerp indeelt. SISO is de basis voor de systematische catalogus en wordt gebruikt als plaatsingssyteem. Zo maakt SISO uw bibliotheekcollectie toegankelijk en vinden uw bezoekers makkelijk de weg in uw bibliotheek. SISO is gebaseerd op een logische en universele indeling van de wetenschappen. Alle wetenschappen zijn verdeeld in nummers en hiƫrarchisch geordend. Hoofdrubrieken worden onderverdeeld in onderrubrieken, deelrubrieken, kleine rubrieken en bijrubrieken.