A ring opening symbol in a SMILES string may have an associated explicit or stereo bond preceding it. Since this symbol is eliminated in the transformation to DeepSMILES, the only way to preserve the information is to move it to the ring closing symbol. For example, the SMILES C=2CCC2 is encoded as CCCC=4. Similarly, the SMILES ClC/1=C/CCCCN1 is encoded as ClC1=C/CCCCN\7 (note the change in bond direction).