Higher bond orders than 2 are considered rare in such configurations but they influence the hybridisation and structural configuration of the scaffold as strongly as exocyclic or exolinker double-bonds. Another crucial aspect to consider here is the synthetic accessibility of the represented scaffolds that is significantly influenced by the presence or absence of exocyclic or exolinker multi-bonds. Additionally, two more abstract scaffold representations taken from Molecular Anatomy are available in Scaffold Generator: basic framework and basic wireframe . Similar abstracted scaffold definitions have been described in earlier works as well, like the graph framework by Bemis and Murcko (analogous to basic wireframe) or the aryl cyclic system by Xu and Johnson (analogous to basic framework), but the naming was chosen here in analogy to Molecular Anatomy. A fifth scaffold type was analogously termed elemental wireframe. Here, all bonds are abstracted to single bonds, but hetero atoms are preserved (Figure ). For the creation of scaffolds of all types, the CDK MurckoFragmenter class is used internally and the extracted Murcko framework is post-processed according to the chosen scaffold type if necessary. If a given molecular structure has no rings, no scaffold can be extracted and an empty IAtomContainer instance is returned.