Recent research in software architecture has reasserted an emphasis on keeping track of design decisions and their rationales during the development process, that is, on maintaining architectural knowledge (AK). This knowledge takes the form of explicit assets, interrelated in decision networks. We argue that the relationships structuring these networks contain valuable information, specially those describing negative semantics. For this reason, we have extended an architecture-centric, modeldriven development process, ATRIUM, which already provides support for AK, with new AK relationships to define AK as a network of knowledge.