The datastore for the BGS digital field data capture system contains databases that have been collected by field geologists and geoscientists using the MIDAS Tablet PCs. The databases replicate (in simple terms) the information and field observations that used to be recorded on paper fieldslips, notebooks and cameras. Depending on what is being mapped, each database can hold data from a complete series of field seasons, and contains points, lines, polygons, map face notes, sketches, photographs, tagged text, and structured data such as measurements and descriptions constrained by dictionaries and standards. Every item collected in the field using this system is attributed with a Unique User ID (UUID) that is constructed using the geologists ID and the date and time (to the second), along with a grid reference aided by a built-in EGNOS (European Geostationary Navigation Overlay Service) -enabled GPS (Global Positioning System). The store contains data collected across the UK and overseas. The scale varies depending on the project. MIDAS was first used in 2006 and each year more field teams are using it to replace pencil and paper records. The data are verified in this fully-relational datastore and transferred from here into the appropriate corporate databases for further manipulation.