RESO Data Dictionary
The BrokerFold Team — Product + Engineering
Last reviewed
The RESO Data Dictionary is the real estate industry’s standard
vocabulary for listing data: an agreed set of field names, definitions,
and permitted values maintained by the Real Estate Standards
Organization (RESO). It is the reason a listing’s price is ListPrice and its
status is StandardStatus on feeds from different boards, instead of
every MLS inventing its own spelling for the same fact.
What it standardizes
Before the Dictionary, each MLS named its data however it liked, and every software vendor maintained a hand-built translation table per market. The Dictionary replaces that with common names, agreed meanings, and controlled value lists — statuses, property types, area measurements — covering the resources a listing system needs: the property itself, media, members, offices, open houses. Boards adopt the core and layer local fields on top for market-specific detail, so standardization is a floor, not a ceiling. The gain compounds for anyone operating across markets: software that understands the standard status vocabulary once can reason about a Toronto listing and a Vancouver listing in the same code path, instead of maintaining a parallel set of rules per board.
How it relates to the Web API
The Dictionary and the RESO Web API are sibling standards that solve different halves of one problem: the Dictionary defines what the data is called, the API defines how it travels. A board can adopt both, and modern Canadian feeds — TRREB’s platform, the BC tri-board system, CREA’s national channel — largely do. For a website vendor, the pair means a new board integration starts from a known map instead of a blank page.
Why it matters for your website
No agent ever reads a schema, but a site’s data quality rides on how faithfully the platform maps board fields to what renders on the page. Standard names make ingestion reliable; the local extensions are where diligence shows, because that’s where bedroom counts, maintenance fees, and regional quirks live. Licensing also attaches at the field level on some boards — certain fields may be licensed for public IDX display while others are reserved for signed-in VOW visitors — and a platform can only enforce those rules cleanly because fields have precise, agreed identities. The board-by-board reality of what actually flows is on TRREB data feeds.
Frequently asked questions
Is every MLS field in the Data Dictionary?
No. Boards adopt the standard core and then extend it with local fields for whatever their market cares about — strata details, regional zoning codes, board-specific flags. A vendor consuming a Canadian feed always handles a blend of standard and local fields.
If a platform is Data Dictionary certified, does my website get every field?
No — certification says the software understands the vocabulary, not that the board has licensed the words. Boards license data per feed and sometimes per field, so what renders on your site is set by your board agreements, not by the standard.
Keep reading
- RESO Web API The RESO Web API is the modern standard for moving MLS data between boards and the platforms that display it. What it replaced and why it matters.
- MLS MLS stands for Multiple Listing Service: the cooperative system Canadian real estate boards run to share listings between brokerages.
- TRREB data feeds TRREB distributes listing data through three lanes — IDX, VOW and DLA — over the AMPRE RESO Web API. A vendor's first-hand map of what each carries.
- IDX IDX is the framework that lets a realtor display their board's active MLS listings on their own website. How it works in Canada, board by board.