in automobile industry, and many others. Consequently, a seriesof review articles have appeared to aid in the international effortto develop new lead-free piezoelectric ceramics. These articleshave typically attempted to survey the composition develop-ment process and, in addition, focused on various propertyissues that have arisen: the review by Damjanovic8was oneof the first in the field and touched some specific domain wall-(micro)structure-properties relations, the paper by Shrout andZhang9concentrated on a comparison to PZT, Takenaka et al.10considered mostly compositions based on BNT, while Li et al.11summarized the progress on KNN-based materials. Guidelinesin terms of electronic structure, useful elements, and phase dia-grams were the focus of the paper by Rödel et al.12five yearsago. Other review efforts focused on the effects of dopants onelectrical properties using a large number of tables to classifyproperty changes,13while Aksel and Jones discussed crystal-lographic aspects.14The review by Coondoo et al.15providesan extensive dataset on lead-free piezoceramics, including bis-muth layer structured ferroelectrics and langasites as well as achapter on energy harvesting. Subgroups of lead-free piezoce-ramics are considered by Jo et al.,5in a description of incipientpiezoelectrics and by Shvartsman and Lupascu with consid-eration of lead-free relaxors.16Recently, fatigue of lead-freeferroelectrics has been specifically addressed by Glaum andHoffman.17Finally, a book on lead-free piezoceramics is cur-rently available.18We, therefore, feel that the latest reviews havesurveyed the field very effectively and see no need for a furtherassessment of scientific concepts or extensive discussion of thecomplete literature.