Sort of People: Considerations About the Ontogeny of Autism in the DDC, 1942-2023 traces the ontogeny of autism within the Dewey Decimal System, from the 14th to the 23rd editions. This period marks significant shifts in the psychiatric understanding and societal attitudes toward autism, reflecting the broader dynamics of neurodiversity recognition, the conceptualization of autism as a spectrum, and the influential role of autistic self-advocacy. The study draws on interdisciplinary sources and theoretical frameworks, including Ludwig’s ‘restricted malleability’ and Hacking’s ‘interactive types’ to critically analyse how changes in scientific, political, and social landscapes have influenced the organization of literature on autism in library classification systems. Methodologically, the paper employs a detailed historical review of DDC editions alongside an analysis of literature concerning the classification of various marginalized groups as well as medical, philosophical, and disability advocacy literature to map the shifts in autism's classification. This approach highlights how the language and structure of classification systems both reflect and shape societal attitudes towards autism. The analysis also considers the impact of autistic self-advocacy on challenging and reshaping these classifications, emphasizing the importance of language and representation in the struggle for autistic integration and visibility. The implications of this study extend beyond the specific case of autism classification. It contributes to ongoing debates on the politics of knowledge organization, the role of libraries and classification systems in either perpetuating or challenging societal norms, and the importance of incorporating marginalized perspectives in the creation and dissemination of knowledge. The author is diagnosed autistic.