The Climate and Forecast Metadata Conventions (CF) standard was originally framed as a standard for data written in netCDF format, with model-generated climate forecast data particularly in mind. However, it is equally applicable to observational datasets, and can be used to describe other formats. It is a standard for “use metadata” that aims both to distinguish quantities (such as physical description, units, and prior processing) and to locate the data in space–time. Sponsored by the NetCDF Climate and Forecast Metadata Convention, the current version dates from December 2011.