The language issue in the multi-national and multi-language Yugoslav federation was oftentimes valued as a vital and political problem. This article analyses language policy in the post-war period, when such a language-politics system was formed that assigned no language de iure official status, and parliamentary practice confirmed the differentiation between the four languages of the Yugoslav peoples – Croatian, Serbian, Slovenian and Macedonian. Particular attention is given to language-related provisions in constitutional texts and philological discussions problematizing the question of whether there should exist two orthographic handbooks – Croatian and Serbian – or Croatian and Serbian linguists should create a unitary common handbook which would serve as a normative standard in the territory of the four federal units.