Dear Colleagues, I imagine you will find the article “The 4Rs and crystal structure analysis: reliability, reproducibility, replicability and reusability” of interest. The weblink is https://journals.iucr.org/j/issues/2022/05/00/dv5002/index.html The article is open access. It is a Teaching and Education article in J Appl Cryst. Best wishes, John Emeritus Professor John R Helliwell DSc