Caveats: MLS-data inside-the-box brief (June 2026) — untested clauses, self-reported metrics, contested copyright status

Highest-stakes caveats — counsel required before reliance:

• 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" + 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 — copyright status is NOT settled. The 2017 FCA originality finding was obiter; 2023 FCA 70 revived the question. Do not assume MLS data is copyright-free.
• 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 — the "analyze" word in s.7(c) is broad and untested in this context. An analytics/market-intelligence product could plausibly be argued to breach it. The exact current signed AUA/DLA text must be reviewed.
• 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) — when MLS-sourced sold data becomes lawfully usable (and whether aggregation/de-identification is sufficient) is fact-specific and not bright-line. The 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) DE-ID analogy is DS — counsel review essential.
• 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 — agent-permissioned redistribution survived an injunction only; no court has ruled it lawful. 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 confirms boards actively terminate feeds they deem non-compliant.
• TREB case dealt with VOW (password-protected) publication — did NOT mandate fully public, non-password-protected publication — the 2018 outcome opened VOW (password-protected) publication; it did NOT authorise unrestricted public republication.

Self-reported / inconsistent metrics — do not cite as fact:

• HouseSigma — self-reported "2M+ registered users / 5M+ monthly visits" + "1.9M Active Users / $500M+ Yearly $ Volume"; internally inconsistent across pages — flag — HouseSigma user / visit figures are self-reported marketing, internally inconsistent across pages.
• PropTx Innovations Inc. — TRREB's wholly-owned for-profit/taxable MLS subsidiary; REALM front-end merges land-registry and MLS data; ~70,000 members — "largest real estate board in the world" is TRREB self-marketing; verify independently.
• 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 — comparative-quality framings rest on anonymous practitioner comments (DS). Structural divide is real; the value-judgment is sentiment.

Industry-reported, not primary:

• 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) — the NAR "DD 2.0 within one year" mandate is WAV Group / industry-reported, not confirmed on a RESO/NAR primary page.
• RESO DD 2.1 — draft (44 resources / 2,167 fields / 4,140 lookups), targeted end of Q1 2026, not yet ratified — DD 2.1 end-of-Q1-2026 timing is a forward-looking RESO statement, not a ratified release.

Cross-border nuance:

• Several VOW/IDX rule documents quoted (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"), 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, Seller opt-outs propagate — opting a listing out of VOW forces opt-out of IDX/aggregators too; sellers can disable AVMs and blogging) are US (CVR MLS, Realcomp, CAR, NAR model rules). They illuminate the principles. Ontario operative rules are CREA + PropTx/ITSO board rules. Use Canadian primaries (PropTx Rules PDF, CREA REALTOR® Code, CREA Rule 11) as controlling, not the US analogues.

Sister-brief caveat umbrellas (shared discipline):

• Caveats: information-asymmetry decision-edge brief (June 2026) — vendor-recycled magnitudes + modeled projections — vendor-recycled magnitudes + modeled projections caveat list.
• Caveats for the data-driven-tools brief: vendor self-reporting on conversion; enterprise-scale benchmarks; named-user quotes; macro projections — vendor-self-reported and large-enterprise extrapolation caveat list.