# Mailboxes & Slots: research notes

Date: 2026-10-25. Scope: residential US mail receptacles bought by a single household — curbside post-mount mailboxes, wall-mount mailboxes, and through-door mail slots, including the locking versions of the first two. The taxonomy label bundles "Mailboxes" and "Slots"; USPS and every brand guide treat these as three install-context families with different approval rules, not as different products a buyer compares side by side, so this is one register with `mounting_type` doing the dividing, not three registers. Excluded: cluster box units (CBU) and 4C horizontal mailboxes. These are multi-family/commercial installations bought and installed by a builder, developer or HOA, not an individual household shopper; USPS treats them under a different standard (STD-4C) with their own ownership, parcel-locker-ratio and ADA rules. No sibling leaf in `catalog.json`'s `household` group claims them either; they are simply out of scope for a consumer-facing register and are not swallowed from anywhere. Also excluded: freestanding parcel/package drop boxes sold as a separate product from the mailbox (no USPS approval regime applies to them at all); noted but not covered.

Quote labels: **verbatim** = the sentence in quotation marks was in text I read myself (curl plus HTML-tag-stripping, or pdftotext) or stated as a direct quote by a fetch tool and then confirmed in my own re-read of the raw text; **fetched excerpt** = a fetch tool's summary/paraphrase, not independently re-read as raw text; **search excerpt** = from a search-engine summary, page unreadable. WebSearch reported its budget exhausted at the start of this run (see Report below); every claim in this register comes from WebFetch, curl, or Internet Archive, and every load-bearing number was re-read as raw text with curl + a tag-stripping script before being marked verbatim. No search-excerpt-only numbers are in category.json.

## Seed

Seed run output (recorded verbatim):

- Example: car-tyres... no — this run's example was **kitchen-knives** `steel_hardness`: "a numeric spec that only makes sense as one side of a trade-off, and a visual grammar borrowed from the hobbyist community that puts the trade-off on one axis."
- Persona: "A textile conservator, who thinks in fibre, construction and how something ages."

1. **The mailboxes equivalent of steel hardness is steel gauge on a locking mailbox.** It is a number brands print (Mail Boss: "38 lbs of 2.5mm & 2.0mm 12 & 14 gauge galvanized welded steel", verbatim) that only means something against a trade-off: thicker/lower-gauge steel resists prying but adds weight and cost, and almost no decorative (non-locking) mailbox publishes a gauge at all, so the number is incomparable across most of the catalog — exactly the "needs a judgement attached" problem the knife example describes. **Kept** as `steel_gauge_thickness`, roles `annotation` + `sort_key`, not a split, exactly like the knife example. No existing community visual grammar for it was found, so the "pry-resistance scale" in `visual_grammars` is logged as a proposal, not a borrowed one.
2. **What the textile conservator would notice first is where a mailbox actually fails: not the broad flat panels but the stress points** — the hinge, the mount to the post, the seam where the door latches — the same way a garment's wear concentrates at seams rather than open cloth. This is a real, plausible claim and several brand pages mention stainless hinges and welded (not riveted) construction as upgrades (Mail Boss: "stainless steel hinges"), but I found no source that states where mailboxes specifically fail first, so it does not survive the data check as a sourced claim. **Dropped.** Logged here, not in category.json.

## Sources and what each supports

### Regulator (USPS itself)

**USPS, "How to Set Up & Mount a Mailbox" (usps.com/manage/mailboxes.htm, curl + tag-stripped)**
https://www.usps.com/manage/mailboxes.htm
- verbatim: "A mailbox with the Postmaster General's (PMG) seal of approval meets USPS size and construction standards."
- verbatim: "Position your mailbox 41″ to 45″ from the road surface to the bottom of the mailbox or point of mail entry." / "Place your mailbox 6″ to 8″ back from the curb."
- verbatim post rule: "A 4″ x 4″ wooden support or a 2″-diameter standard steel or aluminum pipe." / "Avoid unyielding and potentially dangerous supports, like heavy metal pipes, concrete posts, and farm equipment" / "Bury your post no more than 24″ deep", attributed to "The Federal Highway Administration".
- verbatim door slot rule: "The opening must be at least 1 1/2″ x 7″." / "The bottom of the slot must be at least 30″ above floor." / "Horizontal slots must have a flap hinged at the top." / "Vertical slots must be hinged on the opposite side from the door's hinges."
- verbatim: "To replace your curbside mailbox with a wall-mounted mailbox, you must get your local postmaster's permission." / "mounted mailboxes are not required to have a PMG seal of approval."
- verbatim privacy-hood rule: "The hood should not project more than 2 1/16″ beyond the inside of the door." / horizontal/vertical hood extent rules.
- Supports: `mounting_type` branch rules, `pmg_approval`, the door-slot facets (`slot_orientation`, `privacy_hood`), the FHWA breakaway-post judgement. Confidence high (primary regulator page).

**USPS, "The Next Generation Mailboxes" (usps.com/packagemailbox/, curl + tag-stripped)**
https://www.usps.com/packagemailbox/
- verbatim: "Replace your small mailbox¹ with a new package-friendly mailbox big enough for all your mail, too." Footnote 1: "If you currently have an individual curbside mailbox."
- verbatim dimensions: "13.63” wide x 7.75” tall on sides, 12" tall at center x 16.5” deep", footnoted "These are the approximate dimensions; each manufacturer may have models that are slightly different."
- verbatim: "Upgrade your current mailbox to one of these USPS approved, package-friendly mailboxes."
- Supports: the `accepts_packages` split as a real, USPS-named product class, not an invented one. Confidence high.

### Spec sheets (leading brands)

**Architectural Mailboxes (Gibraltar Industries), Residential Mailbox Guide (Internet Archive snapshot, curl + tag-stripped; live site returns 403)**
https://web.archive.org/web/2024/https://www.architecturalmailboxes.com/mailbox-buying-guide/
- verbatim: "As the residential mailbox leader and innovator, Architectural has more than 50 years of industry experience. We manufacture millions of mailboxes annually."
- verbatim capacity tiers: Small = "Envelopes – Bundled Mail – Rolled Magazines – Rolled Newspapers"; Medium = Small + "Padded Envelopes – Small Boxes"; Large = Medium + "Shoe Boxes – Small Boxes – Medium Boxes"; Extra Large = "Magazines Laid Flat" + "Shoe Boxes – Small Boxes – Medium Boxes – Large Boxes".
- verbatim materials: steel "deliver outstanding durability, resist damage" with "a powder-coated finish to withstand rust"; aluminum "resist corrosion, won't rust" with a powder-coated finish to "prolong their lifespan"; plastic "made from sturdy polypropylene... will never rust" with "an ultraviolet inhibitor that resists weathering and fading".
- verbatim: curbside/wall-mount/mail-slot three-way split language ("If your mail is delivered at the curb..." / "If your mail carrier delivers mail directly to your home's entrance, you most likely have a wall mount mailbox" / "some have mail slots that are installed in the exterior door").
- verbatim placement: "curbside mailboxes should be installed at a height of 41-45 inches from the road's surface and set back 6-8 inches from the street curb" — second independent source for the USPS figures.
- verbatim: wall-mount boxes "becoming less common due to U.S. Postal Service regulations", "now typically found on existing residences that have been 'grandfathered in'".
- verbatim: mailbox-and-post "letter compatibility code" system on packaging and product pages.
- Supports: `material`, `capacity_tier`, `mounting_type`, second source for height/setback. Confidence high (leading brand, but a 2024 archive snapshot — the live 2026 page returned 403 for this run, consistent with `checks.md`'s note that brand sites increasingly block fetches).

**Mail Boss (Epoch Design LLC), product page for the original Mail Boss locking mailbox (curl + tag-stripped)**
https://mailboss.com/products/mailboss
- verbatim: "38 lbs of 2.5mm & 2.0mm 12 & 14 gauge galvanized welded steel."
- verbatim: "accepts packages up to 1.9"h x 10.25"w and accepts mail bundles, books, prescription medications, magazines and checks. Incoming mail slot deters fishing by hand."
- verbatim: "Heavy-duty, electro-galvanized steel body with heavy duty powder coat finish" / "Patented anti-pry latch locking mechanism" / "High-security lock with 3 laser cut sidewinder keys".
- verbatim: "Curbside Mailbox - Locking - USPS Approved."
- Supports: `steel_gauge_thickness` (first data point), `incoming_slot_size`, `pmg_approval`, the mail-fishing vocabulary term, the locking trade-off (weight/cost). Confidence high — this is the dominant US security-mailbox brand's own spec sheet, read as raw text.

**Mail Boss, installation guide (curl + tag-stripped)**
https://mailboss.myshopify.com/pages/installation-guide
- verbatim: "The USPS delivery requirements state that a mailboxes' point of entry be placed between 6" to 8" back from the street surface or curb and between 41" to 45" from the road surface. The incoming mail slot of your Mail Boss must be 41"-45" above the road surface. (By contrast, with unlocked mailboxes, the bottom of the mailbox must be 41"-45" above the road surface.)"
- Supports: a third independent confirmation of the 41-45"/6-8" figures, and the specific nuance that the *reference point* for the height rule differs between locking (incoming slot) and non-locking (box bottom) mailboxes. Confidence high.

**Budget Mailboxes (authorized Florence/Salsbury dealer), "USPS Mailbox Requirements: The Complete Compliance Guide for 2026" (curl + tag-stripped)**
https://www.budgetmailboxes.com/blog/usps-mailboxes-a-builders-guide-to-compliance
- verbatim: "Curbside units follow USPS STD-7C, which sets the dimensional, materials, and breakaway-post specs for residential roadside delivery. Cluster and 4C horizontal units fall under USPS STD-4C."
- verbatim: "USPS curbside mailboxes must sit 41 to 45 inches above the road surface and 6 to 8 inches back from the curb face." — a fourth independent confirmation.
- verbatim door slot: "Minimum opening: 1.5″ high × 7″ wide" / "Bottom edge: At least 30″ from the floor" / "Hood projection: Cannot exceed 2-1/16″ from the surface of the door or wall" — second independent confirmation of the USPS door-slot figures.
- verbatim locking: "Slot minimum: 1.75″ high × 10″ wide, large enough to accept an unfolded USPS Priority Mail flat-rate envelope without creasing." / "Approved model: Must be USPS-approved; PMG seal required on the unit itself, not just the slot." / "Retrofitting: Locks are not permitted on traditional or contemporary non-locking designs; buyers must select a purpose-built locking model."
- verbatim post: "Approved materials: 4×4 wood or 2-inch diameter standard steel or aluminum pipe" / "Maximum burial depth: 24 inches below ground level" / "The Federal Highway Administration requires breakaway posts that collapse on vehicle impact. The intent is occupant safety."
- verbatim scope-setting: CBU/4C "place full responsibility for purchasing, installing, and maintaining the CBU on the builder or property owner"; "Mandate: Required for all new construction and renovation since October 5, 2006"; parcel-locker ratio "one parcel locker for every five mailbox compartments."
- Supports: second source for the 1.5x7in door slot and 1.75x10in locking-slot minimums (confirms Wikipedia below independently), the breakaway-post safety judgement, the CBU/4C out-of-scope decision, the "can't retrofit a lock" trade-off. Confidence medium-high: this is a retailer's content-marketing blog (kind `primer` here, not `retail_listing`, because it functions as a USPS-standards explainer rather than a product page), and its specific figures match the regulator and two other brand sources independently, which is why it is trusted for the numbers while its STD-7C claim is flagged as a disagreement below.
- Also carries a 14/16-gauge description of Mail Boss-style units elsewhere on the same retailer's site (`budgetmailboxes.com/usps-approved-mailboxes.html`, kind `retail_listing`): verbatim "Made of 14-gauge and 16-gauge galvanized steel, these boxes are nearly indestructible." This disagrees with Mail Boss's own 12/14-gauge figure for its own product; used only to widen `steel_gauge_thickness`'s range to 12-16 gauge (1.6-2.5mm) across brands, not as a single precise number.

### Primer (encyclopedic, independently re-read)

**Wikipedia, "Letter box" (curl + tag-stripped, re-read in full after an initial WebFetch summary)**
https://en.wikipedia.org/wiki/Letter_box
- verbatim: "Currently, US curbside mailboxes are classified as (T) Traditional, (C) Contemporary, or (L) Locking." / "Traditional or Contemporary non-locking curbside mailboxes are approved in three sizes - No. 1, No. 2, or No. 3, measured by minimum interior dimensions." / "The largest acceptable curbside mailbox is the No. 3, which measures 22.81 inches long, 11 inches wide, and 15 inches in height (58 cm x 28 cm x 38 cm) at the peak." / "designs with a slot for incoming mail must be at least 1.75 inches high by 10 inches wide."
- verbatim: "In 2001, the USPS first approved designs for locking curbside mailboxes to stem a rise in identity and mail theft." / "Locking mailboxes are generally constructed of heavy-gauge steel or aluminum plate, though some models are made of roto-moulded polymer plastic."
- verbatim history: "In 1915, the Joroleman mailbox... was approved by the U.S. Post Office" with "an unusual dome-rectangular shape, incorporating a curved, tunnel-shaped roof"; "Constructed of light-gauge painted sheet steel... an arched, tunnel-shape roof, which prevented excessive accumulation of rainwater or snow while resisting deformation"; "After July 1, 1916, the Joroleman mailbox would be the only design approved by the Post Office for new curbside mailbox installations"; "Not until 1923 did the Post Office finally mandate that every household install a mailbox or mail slot."
- verbatim: "postal regulations required be in the form of the traditional dome-rectangular or 'tunnel-top' design first established in 1915. In 1978... postal authorities at last approved a 'contemporary' mailbox specification."
- verbatim (Canada, used only as contrast, not in category.json): Canadian mail-slot minimum "17.5 cm by 4 cm", located "not more than 125 cm and not less than 60 cm from the finished floor line" — different figures from the US rule, confirms the US figures are US-specific, not confused with Canada's.
- verbatim (Europe, used only as contrast): EN 13724:2002 aperture "230–280 mm" or "325–400 mm" width, "30–35 mm" height, mounting "0.7 and 1.7 m" — not used for any US facet, logged to show the US rule is not the only national standard.
- verbatim theft framing: a "2008 RAND Corporation study, citing USPS statistics collected between 2004 and 2007, found that NDCBU thefts constituted 52.7% of all urban neighborhood mail thefts" — about cluster boxes specifically, not single-household curbside boxes; used only as background for why locking exists as a category, not as a single-household theft-rate number.
- Supports: the T/C/L classification and No.1-3 sizes (judgement, since I could not independently re-fetch the primary USPS engineering drawing this traces to), the second source for the 1.75x10in locking-slot minimum, the Joroleman/1915/1923 mechanism history, the "can't retrofit, 2001" locking history, and the CBU exclusion. Confidence high for the article's own text (read in full as raw HTML, not a search summary); medium for how far back the chain to the primary USPS document actually goes, since Wikipedia's own citation for the T/C/L claim is itself a secondary source (a mailbox brand's "USPS Specs" page, which has since changed and no longer carries that content — see Could not reach).

### Could not reach

- `about.usps.com/publications/pub7/*` (USPS Publication 7, the consumer mailbox booklet) — every path returned 403.
- The USPS engineering standard itself (the document the trade calls STD-7B in older material and STD-7C in a 2026 retailer guide) — no public USPS URL for it was found; Wikipedia's own citation for the T/C/L classification is a mailbox brand's "USPS Specs" page (`mailboss.com`, cited in 2013) that no longer carries that content under any URL I could find, including via the Wayback Machine's CDX index (no snapshot).
- `architecturalmailboxes.com` and `gibraltarmail.com` live pages — 403 and a dead-domain redirect to a lander respectively; the Architectural buying guide was read from a 2024 Internet Archive snapshot instead, flagged above.
- `nationalhardware.com`, `baldwinhardware.com` mail-slot pages — 403/404; no second brand spec sheet for door-slot hardware dimensions beyond the regulator and the Budget Mailboxes guide.
- WebSearch: reported "this session has used its web search budget (200 of 200 WebSearch calls)" on the first two queries of this run and was not used again.

## Data points used for derived metrics

None. I looked for an expert mental-math number the way coffee has cost-per-cup or power banks have Wh, and found none that survives: there is no per-unit consumable, no efficiency ratio, and the one plausible candidate (cost per gauge-mm of steel) has no price data behind it and would be invented. `derived_metrics` is omitted from category.json rather than padded with a weak formula.

## Against the existing add-on schema

`zamana-expertise/data/schema-parts/supplies/household/add-ons/mailbox.jsonc` currently has exactly one field: `usps_approved_claimed: boolean | null`. The household-standard (`household-standard.jsonc`) carries `materials` (generic enum, includes `plastic`, `metal_steel`, but no `aluminum`), `mounting_install` (includes `in_ground_post` and `wall_mounted_screw`, which cover curbside and wall-mount, but no door/slot value), and `sizing.weight_capacity`. The supplies-standard carries `high_signal_markdown` and generic `sizing`.

Proposals only; nothing edited in zamana-expertise:

- `usps_approved_claimed` survives as `pmg_approval`, a hard filter sourced to the regulator itself (USPS) — this register's one safety/compliance-standard facet, per the house rule that a governing standard must be a facet when the product carries a safety dimension (here: the breakaway-post vehicle-safety rule and the USPS-defined mail-security design).
- `household-standard.materials`'s generic enum is missing `aluminum` as a distinct value from `metal_steel` — Architectural Mailboxes sells aluminum as a separate, named material line with different care claims (won't rust vs. powder-coat-protected). Kind: enum value addition.
- `household-standard.mounting_install` has no value for a through-door mail slot (it is hardware installed in or beside a door, not "wall-mounted" in the shelf/hook sense the enum otherwise means). Proposed addition: `door_mount` or reuse `over_door`, which already exists in the enum and is a reasonable fit — no new enum value needed if `over_door` is read loosely for this one category. Kind: none strictly needed; flag for review.
- New fields the add-on is missing entirely, because `usps_approved_claimed` alone cannot express the category's real decision tree: `mounting_type` (categorical hard filter — curbside/wall/door-slot are different regulated products, not a style choice), `accepts_packages` (boolean filter), `locking_security` (boolean filter), `steel_gauge_thickness` (numeric annotation, researched, low density expected), `incoming_slot_size` (text annotation, researched), `slot_orientation` and `privacy_hood` (categorical/boolean filters, door-slot branch only).
- `capacity_tier` is proposed as researched/annotation rather than a schema field, because it is a brand merchandising convention (Architectural's own Small/Medium/Large/Extra Large line grouping) rather than a labelled spec field most listings carry — flagged `backfill_cost: medium` for exactly this reason, matching the house lesson about fields that are brand-page-only, not listing-wide.
- Noise the add-on schema should not add: a `material_text` catch-all (covered by `high_signal_markdown` per the base-schema rules in `zamana-expertise/AGENTS.md`); any attempt to encode the historical No.1/No.2/No.3 or T/C/L letter codes as a schema enum — they are a classification scheme for engineering approval, not a buyer-facing spec any listing states, and `capacity_tier` already covers the buyer-facing version of the same idea.

## Branches

- `mounting_type` = curbside_post → ask `accepts_packages`, `locking_security`, `pmg_approval`, `material`; `slot_orientation` and `privacy_hood` irrelevant. Chain: curbside is the only family with a PMG seal requirement and a package-friendly USPS program (USPS NGMB page is curbside-specific: "Replace your small mailbox¹" footnoted "If you currently have an individual curbside mailbox"); door-slot facets describe a different physical object entirely. SUPPORTED.
- `mounting_type` = wall_mount → ask `accepts_packages`, `locking_security`, `material`; `pmg_approval` irrelevant. Chain: USPS verbatim, "mounted mailboxes are not required to have a PMG seal of approval," confirmed independently by Budget Mailboxes' table ("Wall Mount... Postmaster permission required to switch from curbside," with no PMG line, versus Curbside's explicit "PMG approval required"). SUPPORTED.
- `mounting_type` = door_slot → ask `slot_orientation`, `privacy_hood`; `accepts_packages`, `locking_security`, `pmg_approval`, `material`, `capacity_tier`, `steel_gauge_thickness`, `incoming_slot_size` all irrelevant. Chain: a door slot's own USPS minimum opening (1.5 x 7 in, USPS verbatim) is physically too small for any package, so package capacity never applies; the 2001 locking-mailbox approval Wikipedia describes is specific to "locking curbside mailboxes," and no source here describes a USPS-approved locking door slot, so `locking_security` (and the gauge/incoming-slot facets that branch from it) do not apply either; `pmg_approval` is a curbside/locking-box seal (USPS and Budget Mailboxes both describe it as sitting "on the unit itself," i.e., a box, not a slot plate); `material` and `capacity_tier` describe box products, not slot hardware. SUPPORTED, each leg traced to a separate sentence above.
- `accepts_packages` = package_friendly → ask `capacity_tier`. Chain: the USPS NGMB page frames package-friendly boxes as a size upgrade ("Replace your small mailbox with a new package-friendly mailbox big enough for all your mail, too"), and Architectural's tier content lists only start naming boxes at Medium and above ("Small Boxes" first appears at Medium); the capacity-tier question is only useful once the buyer has said they want package room at all. SUPPORTED.
- `accepts_packages` = standard → `capacity_tier` irrelevant. Chain: Architectural's own Small tier content list is "Envelopes – Bundled Mail – Rolled Magazines – Rolled Newspapers" with no boxes at all, so a "letters only" answer already identifies the Small tier without a further question. SUPPORTED.
- `locking_security` = yes → ask `steel_gauge_thickness`, `incoming_slot_size`. Chain: Budget Mailboxes verbatim, "Retrofitting: Locks are not permitted on traditional or contemporary non-locking designs; buyers must select a purpose-built locking model," and that purpose-built model is exactly where gauge (Mail Boss: "12 & 14 gauge") and incoming-slot size (Budget Mailboxes: "Slot minimum: 1.75″ high × 10″ wide") are specified; these two facts do not exist for a non-locking box. SUPPORTED.
- `locking_security` = no → `steel_gauge_thickness`, `incoming_slot_size` irrelevant. Chain: the same sources describe both facets as locking-model-specific; no source here states a gauge or an "incoming slot" (as distinct from the box's one opening) for a decorative, non-locking box. SUPPORTED.

## Noise

Spec-sheet rows seen on brand pages (Mail Boss, Architectural) but deliberately left out of `category.json`:

- Color/finish (Mail Boss sells a "Granite" color variant alongside Black/White/Bronze; Architectural offers similar color lines): cosmetic merchandising choice with no USPS or functional consequence, unlike material (steel/aluminum/plastic), which does carry one. Left out.
- Historical USPS Traditional/Contemporary/Locking letter codes and No.1-3 engineering size classes (Wikipedia): an engineering-approval classification scheme, not a spec any retail listing states to a buyer; `capacity_tier` already covers the buyer-facing equivalent of the same idea (see "Against the existing add-on schema" above).

## Trimmed detail

- `steel_gauge_thickness`: Mail Boss's own product page states "2.5mm & 2.0mm 12 & 14 gauge" for its 38 lb flagship model; a different page on a retailer's own site (Budget Mailboxes, describing Mail Boss-style units generically) says "14-gauge and 16-gauge." These are not the same number. The register's range (1.6 to 2.5mm / 12 to 16 gauge) spans both rather than picking one, and the facet's `backfill_note` says why: brands rarely publish gauge at all outside a security-mailbox product page, so most rows will have no value.
- `pmg_approval`: USPS's own page states the seal "meets USPS size and construction standards" but does not, on this page, name the engineering standard by number. The STD-7B/STD-7C naming question (see Judgements) is logged here rather than asserted as settled in the facet's definition.
- Door-slot dimensions: the European EN 13724:2002 figures (30-35mm aperture height, 0.7-1.7m mount height) and the Canadian figures (17.5 x 4cm, 60-125cm) are both real and both different from the US 1.5x7in/30in-minimum rule. Logged here as a reminder this register is US-specific; not carried into any facet.
- `capacity_tier`: Architectural's four tiers are not accompanied by published inch or cubic-foot thresholds on the page I read; the facet's `values` therefore use the brand's own labels and content lists rather than invented dimension cutoffs.

## Judgements, confidence and disagreement (summary for the record; full claims are in category.json)

- USPS's curbside design rules (height, setback, seal, breakaway post), not the mailbox's material or styling, are what actually standardizes the category — high confidence, four independent sources agree on the core numbers.
- The current engineering standard's letter (STD-7B vs STD-7C) could not be confirmed against a primary USPS document; sources disagree (or one is simply outdated) and this is flagged rather than resolved.
- Mail theft is the stated reason locking mailboxes exist as a USPS-approved category (2001), but the only theft-rate data found (the 2008 RAND/USPS study) is about centralized cluster boxes, not single-household curbside theft, so the theft-risk judgement for an individual household is marked medium confidence, not high.
- Capacity tiers are a brand convention, not a USPS size class, and should not be presented to a reviewer as if USPS defines "Medium."

## Report back (for the workflow, not rendered)

No script misbehaved. `validate.py`, `render.py` and `viewer.py` all ran clean on the first attempt after fixing word-cap overflows locally (see below). WebSearch was exhausted immediately (first two queries of the session); all research after that point used WebFetch, curl with a tag-stripping Python one-liner, and one Internet Archive snapshot (`architecturalmailboxes.com`'s buying guide, since the live page 403s). Source types reached: regulator (USPS, directly), spec sheets (Architectural Mailboxes via archive, Mail Boss via curl), a retailer's standards-explainer blog (Budget Mailboxes), and one encyclopedic primer (Wikipedia, re-read in full as raw HTML rather than trusted from a WebFetch summary). Source types not reached despite trying: the primary USPS engineering standard document itself, and a second independent door-hardware brand's mail-slot spec sheet (National Hardware and Baldwin both blocked). No enthusiast-community or specialist-review source for mailboxes specifically was found in the sources I could reach; the category's "expert talk" turns out to live almost entirely in brand spec sheets and the regulator itself, which is itself a finding (see the report to the user).

## Corrections (2026-10-26)

- Added facet `has_signal_flag` (boolean, listing): the outgoing-mail flag was a routinely listed curbside spec with no facet at all; re-fetched mailboss.com/products/mailboss (sells a "Curbside Mailbox Replacement Flag Kit") and budgetmailboxes.com's builders guide (verbatim: "Flags signal outgoing mail. Carriers pick up posted items... but only when they can see the flag") as its two sources, gated to `curbside_post` only.
- Added facet `exterior_dimensions` (text, researched): no facet made the `accepts_packages` tradeoff's "bigger object at the curb" claim checkable against a real product; sourced to Mail Boss's own product page ("11.2″ W x 13.6″ H x 21.0″ D") and USPS's NGMB page's reference dimensions, gated under `accepts_packages = yes`.
- Added this "Noise" section, naming color/finish and the historical T/C/L/No.1-3 codes as deliberately excluded rows; neither had been named anywhere before this pass.
- Reworded `steel_gauge_thickness`'s `range.typical` text so it states the 1.6-2.5mm span is two sources disagreeing about one flagship locking model, not an industry-wide typical range; `why_experts_care` already carried this but the range text itself read as settled fact.
- Added `evidence: ["mailboss_product_page"]` to the `locking_security` tradeoff and reworded its "~38 lb" claim to attribute it to "one leading maker's flagship" model rather than reading as a category-wide figure; no second independent source for this weight figure was found (checked Budget Mailboxes' builders guide and resale listing page directly; neither states a weight), so the figure is disclosed as single-sourced rather than dropped, since it is itself attributed correctly as one maker's own spec.