Dear colleagues, We would like to encourage you to consider submitting an abstract to the 2023 IUCr Microsymposium “What Every Crystallographer Should Know About Powder Diffraction”, which is sponsored by the Commission on Powder Diffraction and chaired by David Bish, Cora Lind-Kovacs, and Helen Brand. The abstract submission deadline has recently been extended until February 21, 2023. Two excellent invited speakers, Helen Maynard-Casely and Matthew Rowles, will highlight the session. We hope you will share what you have learned about powder diffraction using X-ray or neutron sources (or even electrons!). The full description for this microsymposium can be found below. Hoping to see some of you in Melbourne! Symposium description: Powder diffraction is used extensively in a wide range of disciplines and research areas to provide at times unique and vital structural information about possibly complicated polycrystalline, multiphasic real materials. This includes dealing with amorphous or nanocrystalline materials as well as microstructural and strain aspects. This is quite distinct from the realm of ideally imperfect single crystals with only a single phase that most crystallographers focus on. This and the rather limited information content of a typical powder diffraction pattern, when compared to that of a single crystal diffraction experiment, results in a number of pitfalls for many crystallographers when they start doing powder diffraction. This can, unfortunately, result in the over interpretation of results or the publishing of powder diffraction measurements that do not support the claims of the greater study. This microsymposium will highlight the most serious of these pitfalls and limitations and look at the use of pdCIF, and training tools, to facilitate an improvement in the quality of published powder diffraction results. The congress will be held in Melbourne, Australia, August 22- August 29 2023 (https://iucr2023.org/<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fiucr2023.org%2F&data=05%7C01%7CCora.Lind%40utoledo.edu%7C64745fd817d34294eb4908dad3bca449%7C1d6b1707baa94a3da8f8deabfb3d467b%7C0%7C0%7C638055104481013921%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=HdgwnaX0tOvcfS7Go6rI7BrSjJ2vvSlhia%2FBwzHYemE%3D&reserved=0>). The triennial Congress of the IUCr is the preeminent international scientific meetings for crystallographers worldwide and attracts a large and diverse audience. It is our hope that there will be a strong in-person attendance at the congress and that the speakers in the microsymposium will present their lectures in Melbourne. Best wishes, Dave -- David L. Bish, Professor Emeritus Indiana University Molecular Structure Center Chemistry Building, A421 800 E. Kirkwood Ave. Bloomington IN 47405-7102 812-855-2039