By definition of prioritisation rules, Schuffenhauer et al. intended to create a chemically intuitive classification system which opposes a classification focussing on pharmacophoric elements . Also, its capability to identify biologically active substructural motives is limited because its exploration of possible parent scaffolds is limited due to the prioritisation rules. For this reason, Varin et al. introduced the concept of scaffold networks , where scaffolds are extracted and dissected analogously but without the application of prioritisation rules. In this way, every possible parent scaffold is generated for a given original scaffold and the resulting hierarchy, the scaffold Network, contains multi-parent relationships between its nodes. Varin et al. generated considerably more active scaffolds in primary screening data using scaffold networks compared to the scaffold tree approach. The reason for this is the exhaustive enumeration of parent scaffolds which leads to the scaffold network containing significantly more scaffolds than a scaffold tree. Additionally, a scaffold is not linked to all parent scaffolds that are substructures of it in the scaffold tree, only to the one determined as its characteristic core. As a consequence, this scaffold may be regarded to be less active.