Table of contents

Linked registers

Registers can be linked by CURIEs and foreign keys.

In registers, CURIEs are a datatype, and all new registers will only be linked by CURIEs. Foreign keys are fields, and not defined by a single datatype.

You can find the datatype of any given field ({field}) at{field}.


Any value in a field with a datatype of curie must be a CURIE. In registers, all CURIEs are of the form {prefix}:{key}, where {prefix} is mapped to a base URL of the form https://{register} for a given register ({register}). This means that when the {key} is blank, it references the full set of records in that register.

For example, the organisation field (, which appears in the statistical-geography register, has the datatype curie. In the ‘E09’ record of this register, the value of the organisation field is government-organisation:D4. The {prefix} is government-organisation, which maps to the URL, and the {key} is ‘D4’. The expanded URL is therefore

Foreign keys

Some fields in registers are foreign keys which link to other registers. A given field ({field}) is a foreign key to another register if the register field is populated at{field}.

For example, the local-authority-type field is a foreign key, and has the URL It’s used in the local-authority-eng register. This means that the local-authority-type field for each record in the local-authority-eng register links to a corresponding record in the local-authority-type register.

In the same example, the ‘SHE’ record of the local-authority-eng register has the URL The local-authority-type field here is populated by NMD, so this resolves to the ‘NMD’ record in the local-authority-type register, which has the URL