Prof. A.P. Kiselev is a member of the organizing committee, the head of the program committee of the annual international conference Days of Diffraction. D.Sc. O.V. Motygin is a member of the program committee of the conference Days of Diffraction. A.P. Kiselev and O.V. Motygin are editors of Proceedings of the International Conference Days on Diffraction. Links: [⤤] and [⤤].