BT: [[library science]] --- # Universal Decimal Classification (UDC) > ‘UDC is one of the most widely used classification schemes for all fields of knowledge. It is used in libraries, bibliographic, documentation and information services in over 130 countries around the world and is published in over 40 languages.’[^1] - see also: - ↬ [UDC Structure & Tables](https://udcc.org/index.php/site/page?view=about_structure) - ↬ [UDC Summary](https://udcsummary.info/) - ↬ [Universal Decimal Classification (Vocabulary Server)](https://vocabularyserver.com/udc/en/index.php) - ↬ [Collections Indexed by UDC](https://udcc.org/index.php/site/page?view=collections) [^1]: ‘Universal Decimal Classification’, *UDC Consortium*, accessed 19 December 2022, [https://udcc.org/index.php/site/page?view=about](https://udcc.org/index.php/site/page?view=about).