We note that the NIST-ISODB can contain multiple, different isotherms for the same publication, adsorbent, adsorbate, and temperature. Publications with two or three isotherms recorded under identical conditions often stem from the digitization of multiple figures that display the same isotherm data in different pressure ranges or compared to different adsorbate or adsorbents. Publications with three or more "duplicates" often report adsorption in adsorbents synthesized under different conditions, where the isotherm serves as a benchmark of the quality of the material (e.g., Figure in Ref. 22), or to illustrate the effect of some post-synthetic treatment (e.g., Figure in Ref. 23). In these cases, therefore, the name of the MOF is reported as the same for the digitization, but the sample does contain differences. Other reasons include reporting multiple adsorption-desorption cycles on the same sample. The experimental reproducibility of isotherms in the NIST-ISODB for the same gas-adsorbent pair has been discussed in the literature, e.g., by Sholl and coauthors. Clearly, however, isotherms that have been measured to study the effect of different synthesis conditions or post-synthetic treatments can be expected to differ from each other, unlike measurements of samples that have been synthesized to reproduce the same material, or studies on the same sample by different groups. A notable case is the NIST inter-laboratory study of methane adsorption in zeolite Y, which reports 109 isotherms at the same conditions: different research groups were asked to independently measure the uptake at 298 K as a way of investigating the reproducibility of the measurement. We postpone the filtering of isotherms recorded under apparently identical conditions to a later stage, when more information on these can inform a rational protocol for their selection.