Nodes of this network correspond to entries in the Registry. Nodes are grouped in color-coded circles according to the Registry categories. Categories corresponding to parts are within the blue box on the left side of the figure whereas categories corresponding to designs are located within the red box on the right side. The diameter of the nodes corresponds to the node connectivity. The directed edges indicate that the sequence of one entry is included in the sequence of another entry. Edges are color-coded according to the type of relationship. If most of the edges correspond to natural relations (parts included in designs, and designs included in other designs), it is somewhat surprising that parts can include other parts (yellow edges) and it is unclear why some parts would include design in their sequence (red edges). Detailed analysis of individual entries can be conducted using a Cytoscape [28] file (Figure S1).