heavymap

10 — HeavyMap joining concepts v1

Linear: NIA-10 (extension comment cea459e0, Agent 1 pickup) Built: 2026-09-25 (revised the same day after a second live-read pass: 30 concepts, ledger at 118 rows) · Framework: Spine + Context Band Ladder vocabulary · Status: planning artifact, proposals only Companions: 11-synonym-parallel-ledger-v1.csv / .md (the rows that use these IDs) · 12-authority-scale-and-meta-proposals.md (what to add to claims/fixtures) Inputs: 07, 08, 09 (this ticket) · MCS v4 + AGENTS-MCS.md (read-only) · docs/architecture/ and docs/architecture/vocab/ on niagaraassembly/heavymap main (49893d0) · PR #13 fixtures · live schema reads on 2026-09-25 (see §8)

A joining concept is a stable HeavyMap ID for the job a field does, so fields with different native names can be united, and fields with the same name can be kept apart. Native names are never renamed away: the claim keeps the publisher’s field name and value (see 12), and the concept ID is an extra handle.

1. Ground rules

1. Concept unity is not joinability. nei_id (Niagara NEI) and Welland’s Business Directory ID are both premises-level register keys, so they share premises_register_key. They still share no key with each other, so no join between the two registers exists. A concept says “same job”, never “these two tables can be joined”.
2. A concept is not a band, a reading, or a stamp field.
   • Band (identity … share_export) says where a claim sits on the ladder. A concept lists the bands it may feed.
   • Reading identifier (floor_area_m2, coverage_ratio, employment_interval) is the name of a computed value. Concepts here name the published inputs (floor_area_published, lot_area_published, employment_size_band), which live on the stamp of a reading, never as a copied raw field on the derived_readings rung (claims contract).
   • Stamp fields (observation_on …) are separate. One concept, assessment_roll_context, is stamp-adjacent (its year maps to observation_on) and says so.
3. IDs are lowercase snake_case, ASCII, stable. Renaming needs an aliases: line in this file. A concept ID is never reused for a different job.
4. Families group concepts for grouping in a UI or a filter. A family has a parent ID only where one is useful (constraint_overlay). Families are not bands.
5. Same word, different concept is allowed and expected. The ledger records those as false_friend rows.
6. Grain here means what a claim under the concept attaches to: parcel, footprint, address, register_unit (a premises or facility record), zone_polygon (an overlay/zone that attaches to a unit by point_in_polygon, containment or overlap), jurisdiction_aggregate (counts for a whole county or city: cannot attach to a spine unit).

Display-genre recommendation (documentation only; the user-selectable rule is a later product decision)

Each concept carries three labels and one default: label_ca, label_us, label_neutral, default_genre.

Situation	Default label shown	Native term shown?
Relation same or alias, CA-comparable	Canadian label (ca)	In the stamp or tooltip
Relation near	Canadian label if comparable (ca), otherwise US (us)	Beside the label, always
Relation false_friend	Neutral HeavyMap label (neutral)	Beside the label, always. Never relabelled into the other genre
US-only concept (no Canadian counterpart held)	US label (us)	In the stamp
Label collision: the Canadian label is itself a false friend in the other genre	Neutral label (neutral)	Beside the label

The collision case is real: assessment_roll_key would be “Roll number” in a Canadian genre, and in New York “roll” means the annual assessment roll, not a parcel identifier. Its default is therefore neutral.

2. Coverage against the ticket’s acceptance list

Required by the extension comment	Concept ID(s)
cadastral / unit key	assessment_roll_key, parcel_gis_key (+ assessing_unit_code)
establishment / register key	premises_register_key
zoning or land-use code	zoning_district (+ zoning_site_modifier, official_plan_designation)
assessment / property-class code	assessment_property_class (+ assessment_use_descriptor, assessed_value, assessment_roll_context)
environmental / constraint overlay family	constraint_overlay → flood_hazard_overlay, natural_heritage_overlay, heritage_designation_overlay, planning_policy_overlay
federal activity register family	regulatory_activity_register (facets by authority scale), jurisdiction_activity_aggregate
one derived-reading family	floor_area_published, lot_area_published → readings floor_area_m2, lot_area_m2, coverage_ratio (§6)

3. Catalog

Format per concept: definition · bands it may feed · grain · labels · anchor and example native fields · watch-list · refusal hook. “Live” means the field list or values were read on 2026-09-25; details are in the ledger.

Family A — Unit identity (band identity)

assessment_roll_key

• Definition: the key under which a parcel appears on a jurisdiction’s assessment roll or tax map.
• Bands / grain: identity (native key) · parcel.
• Labels: ca “Roll number” · us “SBL / print key” · neutral “Assessment roll parcel ID” · default neutral (label collision, §1).
• Anchor and examples: NY SBL (20-char), PRINT_KEY (47.18-1-33), SWIS_SBL_ID; Monroe countysbl (26-digit), printkey; Rochester PARCELID, PRINTKEY; Ontario roll number (MPAC’s ARN): St. Catharines ROLL_NUMBER (19-digit), Norfolk ROLLNUMFUL (19) plus three short forms, Haldimand RollNumber (15), NPCA ARN (15) and ASSESSMENT (20).
• Watch: one key appears in several renderings (Norfolk publishes four in one layer; across Ontario sources the roll number now appears at 11, 15, 19 and 20 digits). Print-key zero-padding is county-specific. Cross-county string equality is not a join. Normalisation belongs to the normalize step, not to the ledger.
• Refusal hook: Brant’s parcel layer carries no roll number at all, so not_in_coverage there. See 12 §4: the roll number is openly published by several municipalities, and NPCA publishes an MPAC-derived parcel fabric with ARN for its own area (all twelve Niagara municipalities plus parts of Hamilton and Haldimand). Under HARD-RULES 4/5 (amended 2026-10-17, #61) MPAC-derived data is usable, so the roll number from NPCA is a native key; where no join is accepted yet it is not_joined.

parcel_gis_key

• Definition: a publisher’s GIS-side identifier for a parcel polygon, used to join that publisher’s own parcel, land-use and zoning layers.
• Bands / grain: identity · parcel. Labels: ca “Parcel GIS ID” · us “Municipal parcel ID” · neutral “Publisher parcel ID” · default neutral.
• Anchor and examples: St. Catharines PROPGISID (shared by parcel, landuse and zoning layers), Niagara Falls pID, NYS MUNI_PARCEL_ID (present, unsampled).
• Watch: not the roll number; not a system row id. A parcel row may carry both (St. Catharines does).
• Refusal hook: Welland and Hamilton publish no parcel fabric (spine doc), so the unit stays footprint or address grain.

assessing_unit_code

• Definition: the code of the assessing municipality that accompanies a roll key.
• Bands / grain: identity · attribute of a parcel. Labels: us “SWIS” · ca none held · neutral “Assessing unit code” · default us.
• Anchor and examples: NYS SWIS (6-digit, 145601), CITYTOWN_SWIS.
• Watch: New York’s only. No shared code with Ontario (INTEGRATION.md); cross-border grouping is geometric. Whether an Ontario roll-number prefix encodes the municipality is not verified.
• Refusal hook: not_joined until a SWIS join names a city or town (matches the Erie fixture).

municipality_label

• Definition: the municipality named as text on a record. Not a key.
• Anchor and examples: NEI municipality (‘St Catharines’), NYS MUNI_NAME, Welland Directory City. Monroe’s field named swis belongs here, not to assessing_unit_code (it holds names).
• Watch: spelling drift; NPCA writes ‘CITY OF NIAGARA FALLS’ where NEI writes ‘Niagara Falls’. Map to the spine jurisdiction slug (st-catharines), never mint the slug from the label.

statistical_geography_code

• Definition: a government statistical-geography code carried on a record, used to attach census-style aggregates to a jurisdiction. Not a parcel or facility key.
• Bands / grain: none as a parcel claim. Jurisdiction-level context only. Labels: ca “Census subdivision ID” · us “County FIPS” · neutral “Statistical geography code” · default neutral (the unit levels differ).
• Anchor and examples: NPRI Census Division (CD) Unique ID and Census Sub Division (CSD) Unique ID (same anchor, live); TRI state_county_fips_code (36029 for Erie) and CBP STATE/COUNTY/GEO_ID (near: a county is upper-tier, a CSD is roughly a municipality).
• Watch: this is how aggregates such as CBP and StatCan tables connect to anything: through a jurisdiction, never a unit. It does not make a parcel claim.

civic_address

• Definition: street address text or split parts for a unit.
• Grain: address. Join method: normalized_address, the weakest method; the contract already prefers identifier.
• Anchor and examples: NEI businessstreetnumber + businessstreetname + businessunit; NYS PARCEL_ADDR, LOC_*; Monroe parceladdress*; Rochester SITEADDRESS; Haldimand StreetAddress.
• Watch: restyling (‘2 Broadway’ → ‘2 Broadway Street’) created false departures in the NEI analysis.

legal_description

• Definition: lot / concession / plan or lot-township-range text describing a parcel legally.
• Anchor and examples: Haldimand Legal1..Legal8 (contents unsampled); Monroe description1..description3 (‘Lot 100 Twp 1 Sh Rng’); NPCA Legal_Txt; NPRI Physical Land Survey Description (a route from a facility row to a lot, if parsed).
• Watch: Haldimand’s LegalAddress looks like an address but belongs here. Not a use description.

parcel_fabric_flag

• Definition: a publisher’s record-type or lifecycle flag on a parcel-fabric row.
• Anchor and examples: Brant PARCELCLASS (only value observed: ‘LAND’), Haldimand Status (‘Existing’).
• Watch: never displayed as a class or use. Brant’s PARCELCLASS is the CA↔NY false friend of NY PROP_CLASS.

publisher_row_id

• Definition: system row identifiers (OBJECTID, GlobalID, FID, Obj_id, NEI GSmartID). Excluded from joins. Listed so they are not mistaken for keys.

Family B — Activity registers (bands identity for the native key, activity_registers for the row)

premises_register_key

• Aliases: establishment_register_key (superseded working name).
• Definition: a publisher’s stable key for one premises-level record in an activity register: a local employment survey, a business directory or licence register, or a regulatory facility registry.
• Bands / grain: identity (native key claim, grade joined, method identifier) and activity_registers (the row) · register_unit.
• Facets (register_family): local_survey (NEI), local_directory (Welland), licence_register (Hamilton, unprobed), regulatory (TRI, NPRI, DEC), regulatory_cross_program (EPA FRS).
• Labels: ca “Establishment ID” · us “Facility ID” · neutral “Register premises ID” · default ca for local registers, per-row us/ca for regulatory facets.
• Anchor and examples: nei_id (2022) / NEI_ID (2017–2019); Welland ID; Hamilton LICENSE_NUMBER (licence-level, near: three licence tables with no geometry); tri_facility_id; epa_registry_id / frs_id; NPRI NPRI ID / ID INRP (bilingual header cell, keep whole); NYS DEC DEC_ID, CBSNO, PBSNO, SITE_ID, AUTHORIZATION_NUMBER (five registries, five key names).
• Watch:
  • nei_id keys a premises, not a business: 544 ids kept the id and changed name between 2019 and 2022, against 121 departures. Named premises_register_key (decided by Morgen, 2026-09-25). The extension comment’s working name establishment_register_key is kept as an alias so older references still resolve. The name matters because “establishment” is exactly the word Census CBP uses for a count, not a key (see the CBP false friend below).
  • Edition drift: NEI_ID → nei_id; a first departures run returned zero because of the casing.
  • Register keys never join across registers (NEI ↔ Welland ↔ TRI share nothing).
  • CBP ESTAB is a false friend. It is a count of establishments by NAICS × county × size class, with no key and no unit rows. It belongs to jurisdiction_activity_aggregate.
• Refusal hook: Hamilton publishes no comparable business inventory: not_in_coverage for the register, not “zero employment”.

industry_classification

• Definition: an industry code and its title attached to a register row.
• Bands / grain: activity_registers · register_unit. Labels: ca “NAICS” · us “NAICS” · neutral “Industry classification” · default ca.
• Anchor and examples: NEI primarynaics, industry (title), primarysector; CBP NAICS2017; NPRI NAICS / Code SCIAN (bilingual header; NAICS 4 and 6 in the single-year tables); Welland SectorDescription (free text, near).
• Watch: never equated with zoning_district or assessment_property_class (a 710 parcel is not evidence of NAICS 31–33). NAICS edition per source vintage is not stated. secondarynaics = 0 means “absent”.

employment_size_band

• Definition: a published employment range for a register row.
• Bands / grain: activity_registers · register_unit; feeds reading employment_interval. Default ca.
• Anchor and examples: NEI sizerangeemployees (2022), EmployeeSizeRange (2019), SizeRange_Employees (2017–2018). Near-neighbours: Welland FullTime/PartTime/Seasonal (counts, not a band); Hamilton NUM_1_4…NUM_500_PLUS (aggregate); CBP EMPSZES/EMP (aggregate).
• Watch: the 2019 band field also holds ‘Business Permanently Closed’ (a status quote: register-quotation-only) and 2017 holds ‘Undetermined’ (a refusal-like value). Band edges differ by source. Aggregates cannot attach to a unit.

regulatory_activity_register

• Definition: a regulator’s or licensing body’s register of facilities or licences, with the facts in it (releases, permits, licence status, closure indicator).
• Bands / grain: activity_registers · register_unit. Facets by authority scale: municipal (Hamilton licence tables), provincial/state (DEC registries), federal (NPRI, TRI).
• Anchor and examples: TRI fac_closed_ind, pref_latitude/longitude, pref_accuracy; NPRI per-facility, per-substance release/disposal/transfer quantities with a Units column, plus Latitude/Longitude/Datum; DEC and Hamilton expiry dates (EXPIRATION, EXPIRY_DATE).
• Watch: it corroborates large sites; it is not a register of industry. fac_closed_ind and NEI’s ‘Business Permanently Closed’ are quotation-only words, and an expiry date is not a closure. Facility points join to parcels geometrically, and the regulator’s own accuracy field should gate that (12 §1): TRI has one; NPRI’s 39 Geolocations columns have none. Never sum quantities across substances or units.

jurisdiction_activity_aggregate

• Definition: counts or statistics for a whole jurisdiction.
• Grain: jurisdiction_aggregate: not a claim about any spine unit.
• Anchor and examples: CBP 2022, StatCan NAICS tables, Hamilton Businesses by Employee Count, Welland Business Licenses (id, Description, Year, Bus_count: licence counts by type and year, not licence records).
• Refusal hook: at parcel level the object is not_in_coverage. They attach to a jurisdiction through statistical_geography_code, and can feed a reading or a coverage check (12 §1).

Family C — Land use and assessment (band land_use)

zoning_district

• Definition: the zone a by-law assigns to land, with its code, label and category.
• Bands / grain: land_use · zone_polygon. Facets: code, label, category, by_law_ref (required for comparability).
• Labels: ca “Zoning” · us “Zoning district” · neutral “Zoning district” · default ca.
• Anchor and examples: Welland Zoning + ZoneCat/ZoneCatSym/ZoneDesc; Hamilton ZONING_CODE/ZONING_DESC + PARENT_BY_LAW_NUMBER/BY_LAW_NUMBER; Brant ZONING/STATUS; Niagara County NY ZoneCode; Rochester BISZONING (near: stored on an assessment snapshot).
• Watch: a zone code means nothing without its by-law (Hamilton has eight parent by-laws; Niagara Falls unions four). Welland packs holding, zone and exception in one string (H-RH-111). Null-attribute polygons are gaps. “Industrial” here is a use regime: false friend of NY PROP_CLASS 700–799. The NYS statewide parcel layer holds no zoning.

zoning_site_modifier

• Definition: an exception or holding provision attached to a zone.
• Anchor and examples: Hamilton EXCEPTION1..3, HOLDING1..3 (each with by-law and URL).
• Watch: rides with the zoning claim; it is not a separate rung. Where a publisher packs it into the code (Welland), the normalize step must split it.

official_plan_designation

• Definition: a land-use designation from an official plan: policy, not regulation.
• Labels: ca “Designation” · us none held · default ca. Uses the ladder’s own word (“Designation, zoning, property class”).
• Anchor and examples: Niagara Falls DESIGNAT; Brant OP_Designation (+ Within_SAB, Within_BUA); St. Catharines DISTRICT_LANDUSE_DESIGNATION / GENERAL_LANDUSE_DESIGNATION; Welland OP Schedule B Adopted_OP, Other_Use, SiteSpec.
• Watch: never presented as zoning. SiteSpec is near to zoning_site_modifier.

assessment_property_class

• Definition: the assessor’s classification of a property for taxation.
• Bands / grain: land_use (stamped as “property class, not zoning, not NAICS”) · parcel. Labels: ca “Property code” (MPAC’s PropCode) · us “Property class” · neutral “Assessment property class” · default neutral (changed from us after the second live pass: an Ontario code is now observed, but the two code tables are not comparable code-for-code).
• Anchor and examples: NYS PROP_CLASS (string 710), Monroe propertyclass (integer 710), Rochester CLASSCD/CLASSDSCRP; coarse near-neighbours Rochester PROPERTYTYPE/RESCOM; Ontario NPCA Parcels Cityview PropCode (3-digit MPAC code, 218 distinct values; code table not read).
• Watch: same code, different label text across publishers (710 ‘Manufacture’ vs ‘Manufacturer’). Rochester’s rows read PROPERTYTYPE ‘Industrial’ and RESCOM ‘C’ together. Brant PARCELCLASS is a false friend. The NPCA layer’s licence is unverified (12 §4).

assessment_use_descriptor

• Definition: the assessor’s building-use code inside a class.
• Anchor and examples: NYS USED_AS_CODE/USED_AS_DESC (F09 ‘Light mfg’, F03 ‘Dstr wrhouse’, E02 ‘Walk-up off’ all seen on class 710).
• Watch: class and use can disagree inside one record, so a class 710 parcel is not necessarily a manufacturing building.

assessed_value

• Definition: a monetary value on the assessment roll, with facets assessed, land, taxable, market_estimate.
• Bands: land_use (claim or refusal beside the class, as in the Welland fixture). Default us (Ontario’s MPAC property class is usable under HARD-RULES 4/5 (amended 2026-10-17, #61); assessed value is not_in_coverage in the layers read).
• Anchor and examples: NYS TOTAL_AV/LAND_AV; Monroe totalassessedvalue; Rochester CURRENT_TOTAL_VALUE.
• Watch: FULL_MARKET_VAL and CURRENT_TAXABLE_VALUE are near, not assessed value. Keep apart in any calculation.

assessment_roll_context

• Definition: the roll’s year and section. Stamp-adjacent: the year maps to observation_on.
• Anchor and examples: NYS ROLL_YR (2025), SPATIAL_YR; Monroe rollyear (2026); ROLL_SECTION (code) / rollsection (label ‘Taxable’).
• Watch: neighbouring counties carry different roll years. The geometry year and the roll year are two dates and both must survive. “Roll” is the false friend of Ontario “roll number”.

Family D — Constraint overlays (band constraints)

constraint_overlay (family parent; no rows of its own)

• Definition: an overlay or encumbrance a joined source states, named by its authority and never summed. Grain is usually zone_polygon (join by point_in_polygon, containment or overlap with a stated threshold), but the read layers show three geometries: polygons (NPCA, FEMA, PSEZ, BOA), a polyline hazard limit (Haldimand Flood Hazard Limit) and points (Niagara heritage). Lines and points need a stated distance or side rule, not point_in_polygon.
• Watch: a filled negative is allowed only inside a layer’s own coverage; a missing overlay is not_joined or not_in_coverage, never “clear”. NPCA says its floodplain layer is not an exhaustive inventory, so absence there proves nothing. One HeavyMap concept spans many services, one per publisher/family (NES publishes one service per family, keyed by series_cod).

Children (each row names its authority; authority_scale is proposed in 12):

• flood_hazard_overlay: FEMA NFHL zones (FLD_ZONE, SFHA_TF; read from a mirror), NPCA regulation lands (2,537) and regulated floodplain (1,316; almost attribute-free), Haldimand Flood Hazard Limit (polyline with Elevation, Uprush, layer id 31).
• natural_heritage_overlay: Niagara NES series (series_cod, layername), NHS, wetlands and woodlands.
• heritage_designation_overlay: Niagara Designated Heritage Properties (318 points: SITE_NAME, ADDRESS, MUNICIPALITY), Welland Designated Heritage Parcels (31 polygons with Parcel_No).
• planning_policy_overlay: PSEZ (31 polygons Ontario-wide, dated 2019/2020; Hamilton 3, Brantford 2, Haldimand 1, none in Niagara Region), growth-boundary flags (Brant Within_SAB/Within_BUA), NY BOA (BOA_Name, Date_des), Niagara Falls Brownfield CIP (three attributes). Band: constraints (decided by Morgen, 2026-09-25), each claim named by its authority. “Brownfield” is a four-way false friend across BOA, CIP, Ontario RSC and OSM.

Family E — Derived-reading inputs (feed band derived_readings; never copied forward as raw fields)

floor_area_published

• Definition: a published building floor area, in the source’s unit.
• Anchor and examples: NYS GFA (integer sq ft; populated on 1,046 of 1,159 Erie 700-series parcels); NEI indoorgfa (premises indoor area, unit unstated: near; absent from the 2022 CSV header read this pass).
• Watch: SQFT_LIVING and Monroe squarefeetlivingarea are habitable residential area (false friend, null on industrial rows). Monroe offers no GFA. NYS SQ_FT is lot area (lot_area_published), even though INTEGRATION.md groups it with floor area.

lot_area_published

• Definition: a published parcel/lot area (acres, sq ft or m²), assessor-stated or geometry-computed.
• Anchor and examples: NYS ACRES (assessor) vs CALC_ACRES (geometry), SQ_FT; Monroe acres; Norfolk Acres; Rochester STATEDAREA; Niagara Falls AREA_SQM.
• Watch: zero is used as “unknown” (SQ_FT = 0, STATEDAREA ‘0.00’, ACRES 0.01 beside CALC_ACRES 11.59). A zero is never carried forward as a quantity (12 §3).

Family F — Presentation-tier (D-13)

owner_of_record

• Definition: owner name and mailing fields on an assessment record.
• Watch: per D-13: retain at ingest, decide tier at presentation. Public record in NY under Real Property Tax Law. PCDP v1 has no owner rung and the fixtures carry none, so no ledger row sets a band. Examples: NYS PRIMARY_OWNER, ADD_OWNER, MAIL_*; Rochester OWNERNME1; NPCA Parcels Cityview Owner (field present, values deliberately not sampled). Per 08, the Ontario municipal layers checked carry no owner field, and the Ontario municipal parcel layers read here (Norfolk, Haldimand, Brant, St. Catharines, Niagara Falls) showed none. The NPCA layer is the exception, which makes its licence question (12 §4) a D-13 question too.

owner_category

• Definition: a non-identifying owner-type code. NYS OWNER_TYPE (value ‘8’ on every sampled Erie row; meaning not verified). Candidate for an earlier tier than the name.

4. Concept-to-concept relations

Pair	Relation	Note
premises_register_key (local) ↔ premises_register_key (regulatory)	near	Same job, different registers, no shared key.
zoning_district ↔ assessment_property_class	different concepts, false-friend pair	“Industrial” appears in both and means a use regime vs an assessed class.
official_plan_designation ↔ zoning_district	different concepts	Policy vs regulation.
zoning_site_modifier ↔ official_plan_designation (SiteSpec)	near	Plan-level vs by-law-level exception.
assessed_value (assessed) ↔ assessed_value (market, taxable)	near	Facets of one concept; not interchangeable.
floor_area_published ↔ lot_area_published	different concepts	NYS SQ_FT sits on the lot side.
assessment_roll_key ↔ assessment_roll_context	different concepts	The “roll” false friend.
flood_hazard_overlay (FEMA zone) ↔ (NPCA regulation limit)	near	Hazard zone vs regulatory limit.

5. Deliberately not concepts

• Owner name as a ladder object. Handled as tiering (D-13), not a rung.
• Sector or “industrial” scores. No composite or opaque scores; readings only.
• Cross-border unified key. The spine already refuses to invent one.
• CBP ESTAB as a register key. False friend, filed under aggregate.

6. Reading identifiers (illustrative catalog, not closed)

Reading	Inputs (concepts)	Notes / refusal
floor_area_m2 (existing)	floor_area_published	Keep source unit on the stamp. not_in_coverage when none published (Monroe, Ontario municipalities in this dig).
coverage_ratio (existing)	footprint area, lot_area_m2	Never 0: refuse with the missing input’s reason.
employment_interval (existing)	employment_size_band	Carry the band as a range; not a point value.
lot_area_m2 (proposed new)	lot_area_published	Needed as the denominator of coverage_ratio. Reject sentinel zeros (see 12 §3).

Other readings from 04-uk-capability-glean.md (containment deltas, register-agreement confidence, gap distance) are deliberately left for a later ticket.

7. Open questions for Morgen

1. Keep establishment_register_key, or rename to premises_register_key? Decided 2026-09-25: premises_register_key, with the old name kept as an alias.
2. Confirm the default genres: assessment_roll_key, parcel_gis_key, assessment_property_class (changed from us) and statistical_geography_code default to neutral; assessed_value to us; everything else ca.
3. planning_policy_overlay band Decided 2026-09-25: constraints.
4. Is lot_area_m2 welcome as a named reading?
5. NPCA’s public MPAC-derived parcel fabric (12 §4): does OGL v2 as stated on the item actually cover HeavyMap’s use? Resolved 2026-10-17 by HARD-RULES 4/5 (amended 2026-10-17, #61): licences don’t gate, so the MPAC roll is no longer not_licensed; the “no parcel fabric” statements for Welland and Hamilton should be revisited.

8. Evidence and method

• Live reads, 2026-09-25, public read-only endpoints, no keys, in two passes. Pass 1: ArcGIS REST ?f=json field lists and a few value samples for NYS Tax Parcels Public, Monroe Parcels_Public, Rochester TaxParcel2024, Norfolk, Haldimand, Brant, St. Catharines, Niagara Falls, Welland, Hamilton, NES; NEI 2017/2019/2022 CSV headers via HTTP Range; EPA Envirofacts tri_facility; Census CBP variables.json. Pass 2: Hamilton licence tables, Welland licence and heritage layers, NYS DEC registries, BOA and Brownfield CIP, Niagara heritage, Haldimand flood limit (layer 31), NPCA’s ArcGIS Online services (fields, counts, item metadata), the PSEZ shapefile (DBF read), FEMA flood zones via an ArcGIS Living Atlas mirror, and NPRI via the ECCC data mart’s real API (data-donnees.az.ec.gc.ca/api, found in the page’s JavaScript bundle; CSV headers by Range). Raw responses were kept in the session scratchpad, not in the repo.
• Still not read: the MPAC product itself (not held); FEMA’s authoritative host (hazards.fema.gov reset the connection on three paths); the NPCA licence PDF (the item’s link returns 404); Niagara County NY parcels (still Token Required on a re-check); CBP data queries (need an API key); NYS Building Footprints layer 0 (index moved); NPCA owner values (deliberately not sampled) and the MPAC property-code table. The ledger now has no unverified or catalog_only rows; the remaining documented rows are repo-doc evidence not re-read live.
• Documented, not re-read: NEI cross-year behaviour (niagara-atlas/logs/2026-08-23.md), D-13, INTEGRATION.md crosswalk, MCS v4 rows, 07/08/09 (read-only, not edited).
• Not edited: MCS, 07, 08, 09, docs/, PR #13, the Linear ticket state.