Since the original table by Barresi and Hindsgaul does not include the full structure of the donors and acceptors we created a simplified model, which takes the fingerprint of the leaving group and the C-2 substituent instead of the full fingerprint of the donor as input. The input representation for the original "full" model and the simplified model are given in Table with the results for all three prediction steps. Restricting the description of the reactants gives a minor drop in performance, but the overall performance for the CAS dataset is still reasonable. However, when the simplified model is applied to the external Barresi-Hindsgaul test set, the performance drops significantly, and the only reasonable predictions are those of the major anomeric product. Interestingly, the predominant solvents, activators, and temperatures follow the same trend as observed in the CAS dataset (Section S2.4). Thus, the drop in performance cannot be entirely attributed to a lack generalization with respect to these components. One major difference between the two datasets is the time of publication. The CAS dataset contains glycosylations published between 2010 and 2015, whereas all the glycosylation reactions in the Barresi-Hindsgaul dataset were published in 1994. Hence, the practices within carbohydrate chemistry regarding reporting anomeric ratios (e.g., how precise is the reported anomeric ratio, is it determined from the crude reaction mixture or after purification, is the observation of a minor anomer reported) are expected to have changed due to an increased focus on stereoselective reactions and advances in analytical methods. The differences in the practices of reporting anomeric ratios might serve as confounding variables, leading to a drop in performance. We would like to stress the importance of reporting anomeric ratios even when it might not seem important and using reproducible reaction conditions, as consistently reported literature data will be helpful for building ML tools, which will hopefully be beneficial for the carbohydrate chemistry community in the future.