Also, examples of resolved USU cases were shown in order to highlight how they were turned into a known sources of uncertainty in the past. For instance, three examples were given ( 235 U(n,f) cross sections as a function of time, particle leakage effects in ionization chambers, and 232 Th(n,γ) measurements adversely impacted by water in the sample) where the need to introduce an USU component could be avoided by understanding the physics effect causing the scatter in the data. In these cases, it was recommended to reject **data** that cannot be corrected for this effect rather than increasing uncertainties of the **data** with an introduced uncertainty contribution attributed to USU. This recommendation is based on the fact that the evaluated mean values might be biased by clearly wrong **data** from a physics point of view if the uncertainties are just increased rather than the mean values corrected. These examples also showcase that USU effects can be reduced or even eliminated by studying the physics cause for the discrepancy in the **data** by dedicated experiments that are designed to investigate the possible effects.