COST Action 18230 INDCOR (Interactive Narrative Design for Complexity Representations) is an interdisciplinary network of researchers and practitioners intended to further the use of interactive digital narratives (IDN1) to represent highly complex topics. IDN possess crucial advantages in this regard, but more knowledge is needed to realize these advantages in broad usage by media producers and the general public. The lack of a shared vocabulary is a crucial obstacle on the path to a generalized, accessible body of IDN knowledge. This white paper frames the situation from the perspective of INDCOR and describes the creation of an online encyclopedia as a means to overcome this issue. Two similar and successful projects (The Living Handbook of Narratology and the Stanford Encyclopedia of Philosophy) serve as examples for this effort, showing how community-authored encyclopedias can provide high-quality content. The authors introduce a taxonomy based on an overarching analytical framework (SPP model) as the foundational element of the encyclopedia, and detail editorial procedures for the project, including a peer-review process, designed to assure high academic quality and relevance of encyclopedia entries. Also, a sample entry provides guidance for authors.