This chapter presents the principles underlying the syntactic annotation and in particular the reasons for separating this annotation into two levels, micro and macrosyntax, presented in Chapters 4 and 6. The particular focus on paradigmatic piles (coordination, lists, reformulation, disfluencies, etc., see Chapter 5) is justified, as well as the integration of hard-to-describe elements such as disfluencies or discourse markers at various level of the syntactic structure. Our decision to discard the notion of sentence and replace it by the notions of Illocutionary Units [IUs] and Government Units [GUs] is discussed.