This workshop follows on from the 2012 Workshop on Diffraction Data Deposition at ECM27 in Bergen and Working Group meetings at ECM28 (U. Warwick, UK) and the IUCr Congress (Montreal, Canada). The Bergen Workshop identified the need for a thorough examination of current practice with metadata for raw diffraction data, and the possibility of using such a review to stimulate improved metadata characterization and handling in non-diffraction studies. This workshop will address both requirements. In the wider scene 'Open Data' as a requirement of research publication is accelerating, whether it be derived, processed or raw data. Crystallography as a field compares well with other fields such as astronomy and particle physics in achieving 'open data' and each field finds raw data archiving challenging, especially the square kilometre array (SKA) in radio astronomy, since raw data is obviously the most voluminous. However, volume alone is not the greatest challenge. Stored raw data must be properly described so that its value and reliability can be assessed and understood, and individual data sets must be discoverable and reusable by other researchers, whether associated with formal publications or not. This is where metadata plays a key role. We addressed technical options for achieving raw data archiving in Bergen and favoured flexibility in the physical location of the data sets, but with a key need for assigning DOIs to each raw data set. Interestingly, Nature magazine on 9 July 2015 highlighted 'the cloud' and commercial providers as being a preferred method for genomics data archiving. The change of attitude of the USA NIH, for example, where there were worries over the security of the commercial data store option, is significant.