The possible role of metal clusters and electronic defects in the near-ultraviolet, nanosecond-pulse–laser damage in HfO2/SiO2-pair-based coatings is analyzed using experimental results on absorption and damage in HfO2 monolayers with and without artificially introduced Hf nanoscale absorbers. These studies reveal a damage mechanism specific to HfO2/SiO2 pair combination comprised of a high-melting-point material (HfO2), where absorption starts, and a lower-melting-point material (SiO2), where absorption can be initiated upon reaching the critical temperature. Based on this analysis we discuss possible modifications to coating designs and desirable properties of high- and low-index materials that might lead to improve nanosecond, near-ultraviolet laser-damage performance.