Canonical SMILES are analogous to the naming convention of a chemical structure, where any of the functional groups can, in principle, be placed at any position, or we could start from any of the branches in the structure, but the International Union of Pure and Applied Chemistry (IUPAC) convention dictates a certain naming convention . Similarly, canonical SMILES are considered to be the IUPAC analogs for SMILES, since in this case also the atoms could be enumerated starting with different branches . Canonical SMILES were generated using RDKit .