<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Dear Colleagues,<div>I imagine you will find the article “The 4Rs and crystal structure analysis: reliability, reproducibility, replicability and reusability” of interest. The weblink is <a href="https://journals.iucr.org/j/issues/2022/05/00/dv5002/index.html">https://journals.iucr.org/j/issues/2022/05/00/dv5002/index.html</a></div><div>The article is open access. It is a Teaching and Education article in J Appl Cryst.</div><div>Best wishes,</div><div>John <br><br><div dir="ltr">Emeritus Professor John R Helliwell DSc<div><br></div><div><div><br></div></div><div><br></div></div></div></body></html>