Аннотация:The article focuses on one type of logico-semantic relation and its markers traditionally identified in Russian grammar as “explanatory” (pojasnitel’nye). It is argued that the term “explanation” designates the communicative function of a given text element and, therefore, is inappropriate when applied to logico-semantic relations. Furthermore, considering the heterogeneity of ‘explanatory’ markers, it is suggested that they form two distinct groups. The first group conveys the semantic relation of specification (a imenno, točnee, naprimer, vključaja, etc.). The second group consists of reformulation markers, which may act either as explanation (to est’) or as paraphrase (inymi slovami, etc.). The article then highlights the semantics and the function of the reformulation marker to est’ and points out its distinctive properties in comparison with other markers showing similar logico-semantic relations.