Based on previous researchers’ criticism of Euro-American bias inherent to universal analogue and digital knowledge organisation systems, this combined qualitative and quantitative postcolonial critical discourse analysis investigates the constructed meanings behind the Library of Congress Subject Headings (LCSH) controlled vocabulary hosted by the Word Digital Library’s (WDL) metadata scheme. This is done with a sample of metadata pertaining to their African cultural heritage collection. The study aims to see if the restricted controlled vocabulary exclude and marginalise situated African knowledge thereby conflicting with their ideological imperative of promoting international understanding. The use of postcolonial theory and discourse analysis theory as both the analytical theoretical framework and methodological approach, reveal that Westerncentric terms from colonial discourse dominate but do not constitute the entirety of the discourses represented by the subject headings. Relying on the assumption that the cataloguers select subject headings based on the rule of literary warrant, the reason for this preference imply an unbalanced collection rather than a biased knowledge organisation system. Therefore, the study suggests the creation of positive rhetorical spaces (Olson, 2002) by adding preferred terms that stem from marginalised situated knowledge systems that too are represented by the existing resources. This will allow for several discourses to co-exist achieving thereby a better fit with the culturally inclusionary aims of the WDL not dependent on the limits of their collection. Also acknowledged is metadata’s pragmatic rationale in support of standardisation for enhanced search and discoverability, but questioned is the sustainability of this principle if the goal is to promote equitable understanding and representation to a wide and international user group. Ultimately, recognising the bias within knowledge organisation systems will serve inclusivity more, rather than traditional claims of universality which conceal exclusion.