This page provides the list of changes that have been made to the HSDS schema.


Backwards incompatible schema changes

  • accessibility_for_disabilities table renamed to accessibility

  • physical_address and postal_address combined and renamed to address

  • service_attribute and other_attribute combined and renamed to attribute

  • All id fields now have format uuid

  • eligibility entity removed

  • payment_accepted entity removed

Other schema changes

  • For service

    • added alert

    • added assured_date and assurer_email

    • added eligibility_description

    • added fees_description

    • added last_modified

    • added minimum_age and maximum_age

  • For organization

    • added logo

    • added parent_oranization_id

    • added uri

    • added website

  • organization_identifier entity added

  • For location

    • added external_identifier and external_identifier_type fields

    • added location_type to express if physical or virtual

    • added url for external source for location information

  • taxonomy entity added

  • contact can now have a location

  • cost_option entity added

  • For schedule

    • added attending_type

    • added notes

    • added schedule_link

  • For service_area

    • added extent and extent_type

    • added uri

  • For taxonomy_term

    • added taxonomy_id and taxonomy_detail

    • added name

    • added code

    • added term_uri

  • phone can now have a language.

  • For language

    • added code field for ISO language code

    • added name and note fields

  • description added to program

  • uri added to required_document

Deprecated fields

  • organization fields tax_id and tax_status

  • service fields licenses, fees and wait_time

Other changes

  • Copy edit of all table and field descriptions;

  • Added JSON schemas;

  • Updated datapackage.JSON and example data to reflect schema changes;

  • Updated reference page to reflect schema changes;

  • Updated logical model to reflect schema changes;

  • Updated formatting guidance to reflect schema changes;

  • Updated identifier guidance to differentiate between internal and third-party identifiers;

  • Added reference page on UK compliance;

  • Created new API reference and reference page, removed HSDA pages;


  • Re-added erroneously removed opens_at and closes_at fields to schedule table;

  • Added further guidance on schedules in response to community feedback;

  • Added timezone and count RRULE fields to schedule table


  • Renamed service_taxonomy table to service_attribute to apply terms to services;

  • Renamed taxonomy table to taxonomy_term;

  • Added taxonomy table to describe taxonomies;

  • Added other_attribute table to apply terms to non-service objects;

  • Renamed regular_schedule table to schedule;

  • Changed fields in schedule table to support RRULE-based entries;

  • Added non-normative guidance to documentation;

  • Clarified normative pages;

  • Added ways for standard to be adapted to particular use-cases;

  • Added guidance for extending the standard;

  • Improved consistency of constraints in schema;

  • Fixed various bugs relating to inconsistencies;

  • Added documentation to illustrate classifications and scheduling;

  • Added auto-building ERD


  • Updated logical model: providing guidance on handling multiple foreign keys, and clarifying use of service_at_location;

  • Removing direct location_id from service so that services should always be connected to locations via the service_at_location table;

  • Adding the service_taxonomy table (missing from earlier releases);

  • Adding description to service_area;

  • Updates to the description of the funding table;

  • Updates to the address block to include region, and deprecate additional address fields;

  • Moving fees and interpretations into the service table;

  • Adding missing accreditations and licenses fields;

  • Adding a language field to phone;

  • Adding a missing primary key to the taxonomy table;

  • Fixing the foreign key on accessibility_for_disabilities;

  • Adding format validation for URIs and e-mail addresses to the schema;


  • Bug fixes to schema and documentation

  • Removed redundant documentation pages


  • Final version

  • Changed relationship between location and service from 1:n to n:m


  • Changes based on public comments in v0.8 include:

    • revising revising schedule entities and attributes as recommended,

    • grammatical and punctuation edits,

    • changing SMS attribute to a phone type

    • changed language_line to interpretation_services

  • Released on github as a markdown document

  • Added a datapackage.json example on github


  • Added formatting specification for address, phone, description

v0.4 - v0.7

  • Updated data model based on reviewer comments

  • Tested logical model by importing data from iCarol database

  • Exported data in HSDS format from previous tes

  • Added Open Eligibility taxonomic overlay to logical model using Postgres ltree

  • Tested OE taxonomy by querying the service_taxonomy to return the related service

  • Provided test scripts and example data


  • Refined logical model to conform to Boyce-Codd third normal form

  • Updated datapackage.json to match logical model

  • Included enumerations for entities in datapackage.json

  • Added section on NIEM and relation to specification

  • Made changes based on reviewer comments


  • Added related standards

  • Added use cases based on persona

  • Reformatted the controlled vocabulary.

  • Added a logical model

  • Made changes from comments collected during the second RFC period

  • Added Appendix C: Tabular Data Package description


  • Changes from comment period, workshop comments, and a running summary of comments

  • Directly references RFC4180 for CSV formatting


No changes.