Abstract: A system for maintaining master reference data for entities is disclosed. The system includes multiple reference data sets at multiple different data storages. A reference data set for a particular entity uniquely identifies the particular entity. The system also includes a first master reference data set at a first data storage that is at least as reliable as a second reference data set at a second data storage. In some embodiments, the first data storage can be updated through real-time process or an offline process (e.g., a batch process). The first master reference data set includes at least one data record, and content metadata regarding the data record. In some embodiments, content metadata comprises lineage data that includes each preceding value that was contained in the data record. In some of these embodiments, lineage includes other factors that affected the present and previous values contained in the data record.