In an attempt to preserve high standards, the IUCr set crystallographic norms. The policy was not entirely practical or successful, but it did focus attention on structure validation as a an important issue - and only just in time. An avalanche of structures is now pouring out of X-ray laboratories. The Nonius Kccd diffractometer in Oxford University is used by both professional crystallographers, and chemists doing their own analyses. Quality control has become a big issue, since there is no way that the departmental analyst can supervise all of these determinations.
Retrospective validation poses both problems and danger.