# ReplacementHQ: the page system for the whole platform (round 2, 9 Oct 2026)

Every page sits on one data model: **device → slot → item (part or consumable) → fit record (verdict, limits, maker quote, source, date) → (later) offer**. Templates are shared; what changes per category is a small set of **category components**, chosen by the category's data.

## Templates

| # | Template | Universal or category-specific | What varies by category |
|---|---|---|---|
| 1 | **Universal homepage** | Universal (one page) | Live-category tiles grow as categories go live. "What we may cover" section shrinks as categories move to live. |
| 2 | **Category homepage** (e.g. /3d-printing/) | Universal template | Hero illustration and accent colour; "how to identify your model" help; the category's at-a-glance view (printers: model × material matrix; filters: cartridge × jug matrix; vacuums: model × bag/filter type) |
| 3 | **Brand page** (e.g. /3d-printing/bambu-lab/) | Universal | Only the device list and the brand's identification help. Published only when a brand has 2+ devices. |
| 4 | **Device / model shelf** | Universal frame + **category components** | The drawing (device family outline with numbered slots); slot types (printer: nozzle, plate, tube, belts, materials; coffee: water filter, descaler, cleaning tablets, seals; vacuum: bags, pre-motor filter, post-motor filter, brush bar; jug: cartridge only; hot tub: filter cartridges, chemicals); a **replacement-interval** strip, only where the maker publishes one |
| 5 | **Individual part page** | Universal | The "fits these devices" list (maker-stated only), the maker code field (shown as "not yet verified" when not published), any interval. |
| 6 | **Consumable / material page** | **Category-specific variants** | Printers: *capability* ("can my printer print TPU?": materials the machine can use, with limits). Filters, bags, cartridges: *physical fit* ("does this cartridge fit my jug?": a product that must physically fit). Coffee descaler and hot-tub chemicals: *maker-approved use* ("which descaler does the maker say to use?"). Same evidence card, different question and verdict wording. |
| 7 | **Compatibility answer** | Universal, with category-specific question templates | Verdict words are shared (Fits, Fits with limits, Not recommended, Does not fit). The question form differs: "Can X print Y?", "Does Y fit X?", "What does the maker say to use in X?" |
| 8 | **Search results and no-results** | Universal | Result groups grow with categories (devices, parts, consumables, answers). The no-result page always offers the request box pre-filled. |
| 9 | **Verification and corrections** | Universal | Each category lists its source types (maker manuals, maker store pages, maker support articles). |
| 10 | **Saved devices and reminders (future)** | Universal | The browser keeps "my things" (no account). Reminders only use maker-published intervals (e.g. Bambu's PTFE tube "every two months"; a filter maker's stated cartridge life). |
| 11 | **Request ("cover this next")** | Universal | Structured: device type, brand, model, part, plus free text. Feeds the decision on the next category. |

## Category components (the only per-category design work)
- **Device illustration set:** one outline per device family (bed-slinger printer, enclosed printer, bean-to-cup coffee machine, upright or cylinder vacuum, filter jug, hot tub), each with numbered slot hotspots.
- **Slot vocabulary:** what each numbered part is called in that category.
- **Identification help:** where to find the model number (printer screen, coffee machine base plate, vacuum rating label, jug lid, hot tub control panel).
- **Question template:** capability, physical fit or maker-approved use (template 6).
- **Accent colour:** one per category, used only on that category's tiles, drawings and hub.

## Rules for future-category examples (design demonstrations only)
- Every future-category page or tile is stamped, visibly: **"Illustrative example · not verified · not searchable · not yet available"**.
- No real brand or model names and no compatibility claims for future categories. Use generic devices ("a typical filter jug") and generic items ("replacement cartridge"). No quotes, source links, dates, prices or availability.
- Verdict chips on example pages show the *layout* only, as "Example verdict" placeholders. They must not read as real answers.
- Search must not return example items. Only the 3D printer register is searchable.