The purpose of this thesis is to highlight a problem with the geographical organisation of knowledge in the library classification system Dewey Decimal Classification. World regions are according to the post-war convention divided along international borders, a classification that tends to obscure relations between sociohistorical phenomena in the borderlands between nation-states. Using a comparative analytic method, four such geopolitically defined world regions in Asia were examined - Central Asia, South Asia, Southeast Asia and East Asia - and compared with the Dewey-system’s classification of the same regions. The study finds that the Dewey-system divides the regions according to convention along nation-state lines. Drawing on examples from historical accounts and ethnographic literature as well as academic constructs such as Zomia, The Southeast Asian Massif and Highland Asia, which refer to borderland areas in highland mainland Asia, the author adopted a borderlands optics through which obscured sociohistorical relations between transnational cultural groups were accentuated. The study further finds that such relations are difficult to express in the Dewey-system, the reason being that it divides the past from the present and that the modern world is largely ordered into nation-states and geopolitically divided world regions. The author concludes that the classification prevents library users from seeing relations between documents about and by groups/authors from borderlands in highland mainland Asia. The author suggests that the thesis’ underlying ideas and results can be applied by librarians in the public library work, whereby it can be used pedagogically to critically think with library users about alternative ways to organise knowledge geographically than the dominant.