Prejudice but no pride: The Portuguese Universal Decimal Classification’s labelling of sexual orientation

Critical cataloguing aims to study cases of social injustice, misrepresentation, negative biases, offensive terminologies, and hegemonic and oppressive hierarchical structures in the representation of communities and identities in knowledge organization systems. The aim of this study is to provide a critical analysis of the representation of sexual orientation in the Portuguese Universal Decimal Classification, grounded in a qualitative content analysis method. The results show that the principle of exhaustiveness does not manifest itself in the representation of sexual orientation. The absence of the term ‘heterosexuality’ mirrors the heteronormative hegemony, while the minoritization of ‘lesbianism’, but not of ‘male homosexuality’, reflects the patriarchal hegemony. The representation of sexual orientation carries the historical pathologization of sexual orientations other than heterosexuality. The Portuguese Universal Decimal Classification conveys negative biases and misrepresents sexual orientation in a way that is irreconcilable with present-day reality. Critical thinking must be encouraged within the library community and the Universal Decimal Classification should be promptly revised and updated.