Research notes (capture-layer): inside the MLS box — what an Ontario member agent's account exposes, what goes unused, and what they're licensed to do with it (June 2026)

Status: Capture-layer (Deliverable 1 only) per author framing — not a KB entry or article draft. Three sections kept strictly separate: Inventory / Underused Layer / Licensing Reality.

Seam vs the existing public-data register

The project's separate "Ontario real-estate data source register" documents the OUTSIDE of the MLS box — what is gettable without board/MLS credentials (CREA HPI, StatsCan, Teranet / land-registry sold prices for a fee, municipal open data, post-2018 consumer sold-data portals). THIS capture is the INSIDE: what a credentialed member agent's own account exposes and what they may lawfully do with it. The seam line is credentialed access + the Data Licensing Agreement / Authorized User Agreement.

Flag: the author could not retrieve the register from Drive during the source session — searches on MLS, HPI, land registry, StatsCan, Teranet, HouseSigma, absorption, days on market, Greater Golden Horseshoe all returned empty. The seam is asserted, not cross-checked against the register's actual entries. Verify before any published piece. See Gaps: MLS-data inside-the-box brief (June 2026) — public-data register not located; counsel items.

Section 1 — The inventory (what is inside the MLS via a member account)

The standardised field set — RESO Data Dictionary 2.0:

• RESO Data Dictionary 2.0 — 41 resources / 1,745 fields / 3,683 lookups (ratified Oct 23 2023; effective April 15 2024) — exactly 41 resources / 1,745 fields / 3,683 lookups; ratified Oct 23 2023, effective April 15 2024. RESO's marketing "more than 1,700 fields / 3,100 lookups" is a rounded, non-version-specific figure — flag.
• RESO DD 2.0 — Property resource is 652 fields, organised into 13 groups — the Property resource alone is 652 fields, organised into 13 named groups (Business, Characteristics, Equipment, Farming, Financial, HOA, Listing, Location, OccupantOwner, Structure, Tax, UnitTypes, Utilities).
• RESO DD 2.0 — full resource list with field counts (Property 652, Contacts 91, Member 87, Office 73, …, TransactionManagement 4) — full resource list with field counts (Property 652, Contacts 91, Member 87, Office 73, Media 41, Showing 44, HistoryTransactional 23, etc.).
• RESO DD 2.1 — draft (44 resources / 2,167 fields / 4,140 lookups), targeted end of Q1 2026, not yet ratified — DD 2.1 in draft (44 resources / 2,167 fields / 4,140 lookups), targeted end of Q1 2026, not yet ratified.
• RESO RETS deprecated June 2018; DD 2.0 ratified Oct 23 2023, effective April 15 2024; NAR-affiliated MLS one-year certification (industry-reported ~April 2025) — RETS sunset June 2018; DD 2.0 ratified Oct 2023; effective April 2024; NAR-affiliated MLSs reportedly had to certify within one year (industry-reported, ~April 2025, not RESO-primary-confirmed).

The historical / non-active layer consumers never saw:

• Competition Bureau (Canada 2014) — TRREB MLS "much more detailed than… REALTOR.ca," holds previous prices, comparables, time-on-market — the federal Competition Bureau's own framing: the TRREB MLS holds previous listing & sale prices, comparable history, and time-on-market that REALTOR.ca does not show.
• PropTx / MPAC appraiser product — 3-year residential / 5-year commercial PropTx MLS sales history with full listing details and photos — PropTx/MPAC appraiser product exposes 3-yr residential / 5-yr commercial sales history with full listing details.
• NAR VOW policy — minimum of 3 years of sold data required in IDX/VOW feeds — NAR VOW policy mandates a minimum of 3 years of sold data in IDX/VOW feeds.
• RESO StandardStatus lookups + HistoryTransactional resource — the schema that models the historical layer — the schema for status/history (StandardStatus lookups Active/Backup/Canceled/Closed/Expired/Pending/Withdrawn; HistoryTransactional resource 23 fields).

Built-in stats / CMA / market-intelligence tooling:

• ITSO Matrix — "more than 500 fields across property types, plus CMA tools, land registry data, neighbourhood insights, Authentisign, AnswerLink, and live market statistics" — ITSO Matrix self-described "500+ fields, CMA tools, land-registry data, neighbourhood insights, live market statistics."
• TRREB / PropTx REALM — bundles ListTrac listing analytics, HoodQ 450+ GTA neighbourhood guides, SkySlope forms — TRREB/PropTx REALM bundles ListTrac listing analytics + HoodQ 450+ GTA neighbourhood guides + SkySlope forms.
• TRREB monthly Market Watch — includes "Month's Inventory" (absorption) — TRREB publishes monthly Market Watch report including "Month's Inventory" (absorption).

Programmatic access paths — feed vs screen:

• RESO Web API — REST/JSON on OData v4, OAuth, calls MLS directly (no local DB duplication); NAR requires REALTOR-association MLSs to provide production-level Web API access — modern REST/JSON on OData v4, OAuth, calls the MLS directly, no local duplication; NAR mandates production-level Web API access for REALTOR-association MLSs.
• RESO provides NO data — only standards; data requests go to local MLSs — RESO itself provides NO data; data requests go to local MLSs after agreeing to their licensing.
• CREA Data Distribution Facility (DDF®) — created 2012, opt-in via REALTOR Link®; multiple channels; feeds are consumer-grade (REALTOR.ca-level), NOT the deep layer — CREA Data Distribution Facility (2012), opt-in via REALTOR Link; channels include National Shared Pool, National Franchisor Pool, Member Feed, Real Estate Advertising Website, Partner, Franchisor Direct Feed; feeds carry consumer-grade (REALTOR.ca-level) data, NOT the deep layer.
• IDX (Internet Data Exchange) — NAR-governed reciprocity policy (not a feed), active listings + pending/sold per local option, public display no login — Internet Data Exchange = NAR-governed reciprocity policy (not a feed), letting participants display each other's active (+ pending/sold per local option) listings publicly, no login.
• VOW (Virtual Office Website) — password-protected, requires established broker-consumer relationship, carries the deeper historical/sold/off-market layer — Virtual Office Website: password-protected, requires established broker-consumer relationship; carries the deeper historical/sold/off-market layer.
• Back-office feed — deepest tier, powers CRM / listing / document management; must not be public; requires broker consent — back-office feed is the deepest tier, powers CRM / listing / document management, must not be public.

The actual Ontario systems:

• PropTx Innovations Inc. — TRREB's wholly-owned for-profit/taxable MLS subsidiary; REALM front-end merges land-registry and MLS data; ~70,000 members — TRREB's for-profit/taxable MLS & technology subsidiary; REALM front-end merges land-registry and MLS data; ~70,000 members.
• PropTx MLS Rules — operative version effective Dec 2 2024 (primary PDF) — operative PropTx MLS Rules effective Dec 2 2024 (primary PDF).
• ITSO (Information Technology Systems Ontario) — not-for-profit, established 2020, Matrix™ on CoreLogic/Cotality; Super Subscribers vs Standard Subscribers tiers — ITSO not-for-profit established 2020, runs Matrix (CoreLogic / Cotality); Super Subscribers vs Standard Subscribers tiers.
• Ontario MLS data divide — PropTx (TRREB-led) vs ITSO holdouts; Cornerstone (Waterloo Region) on ITSO with Cotality; single-membership agents must search multiple boards; client-facing duplicate listings + double-counted stats — fracturing landscape; PropTx-led migration vs ITSO holdouts (Cornerstone, BDAR, Brantford); single-membership agents must search multiple boards; client-facing duplicate listings; stats double-count.
• CREA — owns MLS®/REALTOR®/Multiple Listing Service® registered trademarks; licences member boards; runs REALTOR.ca + DDF; sets national By-Laws, Rules, REALTOR® Code, Three Pillars of the MLS® Mark — CREA owns MLS®/REALTOR®/Multiple Listing Service® registered trademarks; licences member boards; runs REALTOR.ca + DDF; sets national By-Laws, Rules, REALTOR® Code, Three Pillars of the MLS® Mark.

Section 2 — The underused layer

• Typical agent uses a sliver of the 1,745-field MLS dataset — active search, a handful of comps for a CMA, posting their own listing — most agents use a sliver: active search + a few comps + their own listing — a fraction of the 1,745-field, multi-year, multi-resource dataset they pay board+MLS dues to access.
• Months of inventory (absorption) = active listings ÷ monthly sales; 0-4 seller / 4-6 balanced / 6+ buyer (Ontario practitioner framing) — months of inventory = active ÷ monthly sales; 0-4 seller / 4-6 balanced / 6+ buyer; rarely run at hyperlocal scale.
• Cancel-and-relist resets DOM to zero — Pasalis-adjacent practitioner (Globe & Mail); condo relistings hit 163pct of sales in mid-October in the 416; GTA condo months-of-inventory 3.1 in September — documented Ontario tactic: cancel-and-relist resets DOM to zero; condo relistings hit 163pct of sales in mid-October in the 416; GTA condo months-of-inventory 3.1 in September.
• Cumulative DOM now displayed in Toronto / Hamilton / Niagara MLSs — eroding the reset tactic — MLSs in Toronto/Hamilton/Niagara now track and display cumulative DOM, eroding the reset tactic.
• HouseSigma — self-reported "2M+ registered users / 5M+ monthly visits" + "1.9M Active Users / $500M+ Yearly $ Volume"; internally inconsistent across pages — flag — HouseSigma self-reported metrics (2M+ registered users, 5M+ monthly web visits) are inconsistent across pages — flag, treat skeptically.
• HouseSigma — "first in Canada to make sold prices publicly available"; inflection point came shortly after the 2018 SCC-final outcome opening sold data on VOWs — HouseSigma's inflection point came shortly after the 2018 SCC-final outcome opening sold data on VOWs; "first in Canada to make sold prices publicly available."
• Consumer portals commoditised the "just-sold" edge — practitioner consensus; portals cannot capture local nuances, off-market activity, or hold-offer strategies — practitioner consensus: consumer apps have watered down the realtor competitive advantage of "just-sold" data; portals cannot capture local nuances, off-market activity, or hold-offer strategies.
• Durable member edge has shifted from headline sold price to the deeper structured layer (relisting chains, sub-market absorption, list-vs-sold spreads, off-market, ListTrac analytics) — strategic implication: portals commoditised the headline sold price; the durable member edge is now the deeper structured layer (full field history, relisting chains, sub-market absorption, list-vs-sold spreads, off-market, ListTrac analytics).

Section 3 — The licensing reality (highest stakes, treated conservatively)

Three concentric circles. Each is treated as a discrete legal posture.

Circle (i) — SEE (use within own practice, advise own clients):

• Even where MLS prohibits displaying sold/expired/withdrawn/pending data, broker-selected comparables for a CMA are permitted ("both on a VOW and in the office") — broker-selected comparables for a CMA are permitted even where consumer-driven display of sold/expired/withdrawn/pending data is restricted. The line: who chose the listings — the consumer (display rules apply) or the broker in the course of brokerage services (permitted).
• MLS data is personal information in the agent's hands; the Authorized User Agreement is a confidentiality agreement (PropTx Rules definitions) — the data is personal information in the agent's hands; the AUA is a confidentiality agreement.

Circle (ii) — FEED / DISPLAY (pull a feed, show it on a website):

• IDX control test — if a third-party aggregation site controls the overall display, the listing fails the test and IDX's built-in consent disappears — IDX subject to a control test: if a third-party aggregator controls the overall display, the listing fails the test and IDX's built-in consent disappears.
• Seller opt-outs propagate — opting a listing out of VOW forces opt-out of IDX/aggregators too; sellers can disable AVMs and blogging — seller can opt out of all internet display; opting out of VOW forces opt-out of IDX/aggregators; sellers can disable AVMs and blogging.
• VOW Terms of Use — registrant must acknowledge relationship + bona fide interest + personal non-commercial use + MLS ownership/copyright; no redistribution/sublicense (PropTx Rules, primary) — VOW Terms of Use require an established broker-consumer relationship, bona fide interest, personal non-commercial use, and acknowledgement of MLS ownership and copyright; bar consumer from copying, redistributing, sublicensing.
• AVP (Affiliated VOW Partner) — rights are derivative of the member's and scoped to operating that member's VOW (PropTx Rules Art. 8; NAR VOW; CVR MLS) — Affiliated VOW Partner rights are derivative of the member's and scoped to operating that member's VOW.

Circle (iii) — BUILD ON / REPUBLISH (most effort, hardest no's):

• PropTx AUA s.7(c) — express prohibition: no decompile / reverse-engineer / disable / modify / analyze / create derivative works of software, MLS Database, BRS Database; s.4 ties to REBBA/TRESA — PropTx AUA s.7(c) expressly forbids decompile / reverse-engineer / disable / modify / analyze / create derivative works of the software / MLS Database / BRS Database; s.4 prohibits use contrary to By-Laws, MLS Rules, MLS Policies, or REBBA/TRESA.
• TREB deploys anti-scraping services, firewalls, IDS, and encrypted token authentication as Technological Protection Measures (TPMs) — TREB deploys anti-scraping services, firewalls, IDS, and encrypted token authentication as Technological Protection Measures (TPMs).

Competition Bureau v TREB (2011-2018) — the landmark case:

• Commissioner of Competition v. Toronto Real Estate Board (2011-2018) — full 7-year timeline; SCC denied TREB's final leave Aug 23 2018 — full 7-year timeline through to SCC dismissal Aug 23 2018.
• TREB VOW restrictions held to be abuse of dominance under Competition Act s.79 (2016 Tribunal redetermination); order requires TREB to stop restricting members' access/use of historical+sale-price data on VOWs — what it OPENED: TREB's VOW exclusions held to be abuse of dominance under Competition Act s.79; order requires TREB to stop restricting member access/use, including display of historical listings and sale prices on VOWs.
• TREB case dealt with VOW (password-protected) publication — did NOT mandate fully public, non-password-protected publication — what it LEFT unsettled: the case dealt with VOW (password-protected) publication, NOT fully public unrestricted republication.
• FCA 2017 (2017 FCA 236) — in obiter, endorsed Tribunal's conclusion that the TREB MLS compilation lacked the originality (skill/judgment/labour) for copyright; TREB "had not put forward persuasive evidence" — in obiter, the FCA endorsed the Tribunal's conclusion that the TREB MLS compilation lacked the originality (skill/judgment/labour) for copyright. The single most consequential — and most contested — point for any builder.
• TREB's PIPEDA-based privacy/business-justification defence failed on the facts — wide use, inconsistent enforcement, no CPO/CIO evidence; principle remains theoretically open — TREB's PIPEDA-based justification failed on the evidence, not in principle; a better-evidenced privacy justification remains theoretically open.

Subsequent scraping / agent-funnelled / feed-termination cases:

• TREB v. Mongohouse (2019) — permanent injunction; scraping MLS by circumventing TPMs is unlawful (Copyright Act s.41 + AUA + third-party licence breaches) — permanent injunction; scraping via TPM circumvention is unlawful (Copyright Act s.41 + AUA breach + third-party licence breaches).
• TRREB v. RE Stats Inc. (Redatum) 2021 FC 30 — Federal Court denied TRREB's interlocutory injunction; data "comes from its clients, which are TRREB members"; copyright question left for trial — Federal Court denied TRREB's interlocutory injunction; data "comes from its clients, which are TRREB members" — agent-permissioned access survived (no ruling it was lawful).
• IMS v. TRREB (2023 FCA 70) — FCA allowed TRREB's copyright claims to proceed; prior 2017 obiter did NOT finally decide originality of this (different/updated) MLS work; copyright is live again, not settled — FCA allowed TRREB's copyright claims to proceed; prior 2017 obiter did NOT finally decide originality of this MLS work; the copyright question is live again, not settled.
• Ojohome Canada Ltd. v. CREA / TRREB (2025, Ont. Sup. Ct.) — TRREB terminated IDX access Oct 2024; CREA restricted DDF Dec 2024; site cut from ~54,000 to ~11,500 listings; injunction to restore access denied — TRREB terminated IDX access (Oct 2024); CREA restricted DDF feed (Dec 2024); brokerage's injunction to restore access denied; site cut from ~54,000 to ~11,500 listings. Boards/CREA actively police feed eligibility.
• PIPEDA has no independent cause of action — complaints must go to the Privacy Commissioner first (s.14); FCA confirmed (Lexology / TRREB v. IMS) — no independent civil action for breach of PIPEDA; complaints must go to the Privacy Commissioner first (s.14).

PIPEDA on the personal information inside listings:

• Ontario has no substantially-similar private-sector privacy law → PIPEDA applies in full to MLS personal info (only BC, AB, QC have substantially-similar laws) — Ontario has no substantially-similar private-sector law (only BC, AB, QC do); PIPEDA applies in full to Ontario real estate.
• OPC Case Summary #2009-002 — sold price + address is personal information; pulling from MLS does NOT qualify for "publicly available" consent exemption (decisive against MLS-sourced republication) — KEY: sold price + address is personal information; pulling it from the MLS does NOT qualify for the "publicly available" consent exemption (even though it would also be in the land registry — the exemption depends on where you collected it from).
• OPC PIPEDA Case #2005-303 (and BCREA #409) — using OTHER agents' MLS sales records in a "top 5 sellers" ad without consent breached Principle 4.3 — using other agents' MLS sales records in a "top 5 sellers" ad without consent breached Principle 4.3; merely using the MLS does not constitute consent.
• CREA Privacy Code (in place since 2001) — 10 PIPEDA principles; brokerages must obtain seller/buyer consent for board collection/use/disclosure and produce proof on request — CREA Privacy Code in place since 2001; 10 PIPEDA principles; brokerages must obtain seller/buyer consent and produce proof on request.
• OPC PIPEDA Case #2009-004 — combining publicly available directory info with geo-demographic stats did NOT create new personal info requiring consent; by analogy, sufficiently aggregated/de-identified MLS market stats likely fall outside PIPEDA consent (DS for the threshold) — combining publicly-available directory info with geo-demographic stats does not create new personal info; by analogy, sufficiently aggregated/de-identified market statistics likely fall outside PIPEDA consent rules — but the de-identification threshold is fact-specific (DS for the MLS-aggregate application).

Rules distilled (R1-R10)

• Rule: treat MLS data access as a contract (DLA / AUA / VOW Terms / IDX policy), not just a login
• Rule: no scraping. TPM circumvention is unlawful (TREB v. Mongohouse permanent injunction)
• Rule: no "derivative works" of the MLS Database. PropTx AUA s.7(c) includes "analyze" — broad, ambiguous, untested. Counsel-required before any analytics product asserts non-breach
• Rule: treat MLS copyright as LIVE, not settled. 2017 FCA originality obiter was revived by 2023 FCA 70 (IMS v. TRREB)
• Rule: do not republish sold price + address from MLS without consent. OPC #2009-002 — MLS-sourced ≠ registry-sourced; the "publicly available" exemption fails when the MLS is the source
• Rule: Ontario has NO substantially-similar private-sector privacy law — PIPEDA applies in full. Do not extrapolate enforcement intensity from Quebec / BC / Alberta
• Rule: do not use MLS® / REALTOR® / Multiple Listing Service® marks as nouns; adjective-only ("MLS® System"); never in business / domain / meta-tag
• Rule: the agent-permissioned (Redatum) seam survived only an injunction — no court has ruled it lawful. Boards actively terminate feeds. Treat as exposed, build resilience
• Rule: the durable member edge has shifted from headline sold price (commoditised post-2018) to the deeper structured layer — build articles + products around that, not the just-sold figure
• Rule: the seam vs the public-data register — this brief is INSIDE the box. Do NOT re-catalog the OUTSIDE proxies (HPI / StatsCan / Teranet / municipal open data / consumer sold portals)

Caveats and gaps

See Caveats: MLS-data inside-the-box brief (June 2026) — untested clauses, self-reported metrics, contested copyright status for the conservative list of untested clauses, self-reported metrics, and contested copyright status. See Gaps: MLS-data inside-the-box brief (June 2026) — public-data register not located; counsel items for the open research items (chief among them: the Drive-side register that the source session could not retrieve).

Sister briefs (existing KB)

Adjacent affirmative + cautionary briefs on data, moats, and licensing-fenced commercial data: Research notes (capture-layer): the affirmative, inward decision-edge case for data intelligence — information asymmetry applied to pricing, demand, risk, retention, targeting (June 2026) (which inward decisions a proprietary information advantage changes), Research brief: Public data as a private moat — building proprietary intelligence from government open data (piece 11 of 15) (public-data moat mechanics), Research brief: The Dataset is the Product — when a service business should own its data (piece 12 of 15) (own vs rent), Research brief: live data and data-driven tools for SMBs — when it's an edge, when it's overkill (June 2026) (live data — edge or overkill).