This paper presents types and annotation layers of reply relations in computer-mediated communication (CMC). Reply relations hold between post units in CMC interactions and describe references from one given post to a previous post. We classify three types of reply relations in CMC interactions: first, technical replies, i. e. the possibility to reply directly to a previous post by clicking a 'reply' button; second, indentations, e. g. in wiki talk pages in which users insert their contributions in the existing talk page by indenting them and third, interpretative reply relations, i. e. the reply action is not realised formally but signalled by other structural or linguistics means such as address markers '@', greetings, citations and/or Q-A structures. We take a look at existing practices in the description and representation of such relations in corpora and examples of chat, Wikipedia talk pages, Twitter and blogs. We then provide an annotation proposal that combines the different levels of description and representation of reply relations and which adheres to the schemas and practices for encoding CMC corpus documents within the TEI framework as defined by the TEI CMC SIG. It constitutes a prerequisite for correctly identifying higher levels of interactional relations such as dialogue acts or discussion trees.Zusammenfassung: Der vorliegende Artikel stellt Typen und Annotationsebenen von Antwortrelationen in der internetbasierten Kommunikation (IBK) vor. Antwortrelationen bestehen zwischen Posts in IBK-Interaktionen und beschreiben Referenzen, die zwischen einem Initialbeitrag und einem Folgebeitrag bestehen. Wir klassifizieren drei Arten von Antwortrelationen in IBK-Interaktionen: erstens, technische Antwortrelationen, welche dadurch gekennzeichnet sind, dass durch das Betätigen einer "Antwort"-Schaltfläche eine Antwort initiiert wird, bspw. in Blogs; zweitens,