Reference data is data that defines the set of permissible values to be used by other data fields. Reference data gains in value when it is widely re-used and widely referenced. Typically, it does not change overly much in terms of definition (apart from occasional revisions). Reference data often is defined by standards organizations (such as country codes as defined in ISO 3166-1).
Typical examples of reference data are:
- Units of measure
- Country codes
- Corporate codes
- Fixed conversion rates (e.g., weight, temperature, and length)
- Calendar (structure and constraints)
Reference data should be distinguished from master data, which represents key business entities such as customers and materials in all the necessary detail (e.g., for customers: number, name, address, and date of account creation). In contrast, reference data usually consists only of a list of permissible values and attached textual descriptions.