The decision towards XML and the tree data model is based on the OHCO assumption of text as an Ordered Hierarchy of Content Objects (DeRose et al. (1990); revised in Renear, Mylonas, and Durand (1993)). Contrasting the original goals (TEI Consortium 2016c) of interoperable long-term archivable data repositories with the status quo, this decision towards XML as the serialisation format needs to be critically questioned – particularly since the TEI Guidelines themselves very early on make clear that the assumption of data model behind XML is an improper simplification (TEI Consortium 2016a):