The following definitions are provisional.
The following terms are used in the documentation:
Catalog contains a collection of purchasable variables (e.g. for a Postal Address).
Ontology refers to a way of defining what information is available, by classifying and categorizing variable types into schemas.
Postcode Address File (PAF) is a database, maintained by the Royal Mail, which contains all known delivery points and postcodes in the United Kingdom.
Postal Address refers to a unique delivery address within the UK.
Provenance refers to the provider and source of a variable.
Schema refers to the formalising of ontologies by organisations such as Cadw (for listed buildings status) or the Valuation Office Agency (for council tax bands).
Variable Identifier uniquely identifies a variable with a particular Provenance.
Variable Type defines a variable's characteristics including the underlying data type, allowable values, and indicative price range.
Variable refers to a piece of information (such as "Bedroom Count" for a property) that may be purchased.