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Data Dictionary

What is the RESO Data Dictionary?

The RESO Data Dictionary is the real estate industry’s universal language for data. It allows a wide range of systems to talk to each other in a seamless manner.

The need for the Data Dictionary arose as the real estate industry evolved from printed MLS books to a digital experience. Thousands of REALTOR® associations and MLSs adopted unique technology systems to serve their local markets. These systems often couldn’t communicate with each other. 

The Data Dictionary is the solution: a standard that ensures every system can speak the same language. It defines real estate data in consistent terms and structures. The Data Dictionary is a template for building systems that are flexible, scalable, and that will more easily integrate with other tools.

Visit the RESO Data Dictionary Wiki for the full list of data fields and options.

Benefits of the RESO Data Dictionary

Using the Data Dictionary creates concrete benefits for professionals and consumers:

  • Simplified integrations: Standardized data moves between systems faster and allows tools to work together more accurately.
  • Faster creation of new tools: Technology built on the standard brings new tools quickly to the market, saving time and money while creating more insightful data.
  • The seal of approval: RESO certification provides a level of trust that data partners can rely upon.
  • Promotion of leadership: The “RESO Certified” logo is a sign that an organization is leading the industry in moving standards forward. 
  • Collaboration with the industry’s best and brightest: Working with RESO’s 800+ member organizations provides significant benefits for industry newcomers and incumbents.

Does standardizing to the Data Dictionary take away flexibility for unique local factors?

While RESO’s Data Dictionary defines a standard for many kinds of data fields, it also allows for local markets to establish custom fields that reflect unique local situations. This can also be done in a standardized way which allows for flexibility while also ensuring interoperability between systems. The local real estate flavor can stay as unique as it always has.

New fields can also be added to the Data Dictionary to support industry needs. By joining RESO and collaborating with its workgroups, members can make suggestions for the expansion of standards. The Data Dictionary is continuously examined and expanded based on input from members across the industry. | VISIT THE DATA DICTIONARY WORKGROUP

RESO Data Dictionary Certification

RESO certifies MLSs, brokers, and technology partners on RESO’s Data Dictionary and Web API standards. In particular, MLSs owned and operated by REALTOR® associations are required by policy of the National Association of REALTORS® to be in compliance with RESO’s standards within 12 months of the standard being ratified by RESO. MLSs can show this compliance with a RESO certification.

Answers to Your Questions

Visit the RESO Certification Resources, or email with questions. 

    RESO Data Dictionary Downloads, Certification Rules, and Guides

    RESO’s End User License Agreement (the “EULA”) is entered into by and between the Real Estate Standards Organization (“RESO”) and the person or entity (“End User”) that is downloading or otherwise obtaining the product associated with this EULA (“RESO Product”).

    By downloading from the links below, you agree to the EULA.

    Data Dictionary Wiki Resources

    The RESO Data Dictionary Wiki contains the resources, fields, and lookups to guide the development of data systems.

    RESO is grateful to the numerous industry experts who have helped craft the Data Dictionary.

      DLU May 15th, 2020