importance of data discoverability: an informatics issue that was not considered by WWARN's designers in the initial phase, when it was assumed that access for external users would be limited to the summary data shown on the WWARN Explorer. Discoverability - the ability of potential outside users to find the data set and easily understand what it contains - is critical if the data are to be reused by any investigator with a legitimate research question that may be addressed by data held in the resource. WWARN took care to develop data management tools that included a full audit trail for the variables that they standardised.