The paper offers a description of Slavic word order systems from the viewpoint of formal typology based on notions such as syntactic type, parametric settings, basic and derived order, linearization constraints, constituency, movement, spell-out, cliticity, clitic clusters, syntax-prosody interface, and grammaticalization. The aim is to classify Slavic word order systems with clitics on the basis of syntactic constraints without dependence on hypotheses about language-specific properties of prosodically deficient elements and to provide a viable typological classification, which can be verified by data from other world's languages.