By the end of this year, hundreds of multiple listing services must take a step that is widely expected to set the stage for tech developers to build more, better, and cheaper agent and broker tools powered by real estate data.

Northern California-based MLS MetroList Services Inc. is the first to take that step, obtaining certification for a set of real estate data standards developed by the nonprofit Real Estate Standards Organization called the RESO Data Dictionary.

Dubbed the “Rosetta Stone” for real estate data, the Data Dictionary is a standardized set of data terms for the most common descriptions of property characteristics used in the industry.

MetroList, which has more than 16,500 members in seven counties, implemented the Data Dictionary with the help of its MLS system vendor, Rapattoni Corp. Rapattoni’s MLS products serve about 200,000 users nationwide.

Brian Tepfer

Brian Tepfer

“The RESO Data Dictionary … ensures that each MLS system speaks the same language, using a common standard that defines all data in consistent terms. Establishing this common standard represents a significant achievement for the industry,” said Brian Tepfer, Rapattoni’s chief technology officer, in a statement.

“We’re thankful to MetroList for leading the charge and we’re excited to be the first MLS vendor to provide our customers with Data Dictionary 1.3 compatibility.”

At its annual meeting in November, the board of the National Association of Realtors approved a policy requiring Realtor-affiliated MLSs to comply with the Data Dictionary by Jan. 1, 2016. The vast majority of the nation’s 850-plus MLSs are Realtor-affiliated.

The Data Dictionary allows third-party vendors to access data from different MLS systems in a standard format, allowing vendors to map MLS data to their apps more quickly thereby saving time and money.

“The standardized mapping of data and delivery of these fields will assist us in releasing products and services to our participants and subscribers,” said Rick Trevino, IT director of MetroList, in a statement.


Robert “Bob” Gottesman

MetroList beta-tested the certification, which assures compliance with the Data Dictionary. Although MLSs and their vendors have to collaborate to implement the standard, only MLSs may obtain Data Dictionary certification because the MLS controls how its data is formatted, according to Robert “Bob” Gottesman, RESO’s executive director.

“If an MLS has a lot-size field as a character field, but the Data Dictionary says it has to be numeric, it is the MLS’s responsibility to either make that change or approve that the change can be made,” he told Inman.

Vendors can receive certification for RESO standards that govern how data is transmitted, however. So far, MLSs and vendors that have achieved such certification include Metropolitan Regional Information Systems Inc. (MRIS), CoreLogic, Terradatum, MLSListings Inc., Trulia, Move Inc., Homes Media Solutions, TLCengine, Midwest Real Estate Data (MRED), MetroList and FBS.

Check out the beginning of our real estate dictionary here.

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