This chapter deals with the person indexation system of Emérillon (also called Teko), a little described Amazonian language. It will focus on the system's most interesting feature: the selection of the obligatory person index out of two series on transitive predicates. Transitive predicates allow only one person index, which is selected according to the relative position of the two arguments on both the person hierarchy 1/2 > 3 and the grammatical relation hierarchy S > O. I argue that this system should be classified as a distinct type of indexation system, here termed 'hierarchical'. The analysis of the hierarchical indexation system of Emérillon, in comparison with other languages, leads to three major theoretical assertions: First, hierarchical systems should be considered alongside major indexation systems such as nominative-accusative and ergative-absolutive. Second, indexation should be distinguished from alignment. And finally, inverse systems should be considered as a subtype of hierarchical systems more generally, rather than the other way around.