As a result of the alvaBuilder fragmentation, the information about the position of the linkers is kept so the complete molecules can be reconstructed from their corresponding fragments. This preserves chemical knowledge inherent to the scaffold and the substitution pattern in the fragments. In contrast, information about the original substitution of a fragment in LigBuilder has to be user-defined as a growing site. That information was not disclosed for the selected fragment libraries and was only available for the RECAP fragments.