CLCTN · TYPE SYSTEM · SUBTYPES · OCTOBER 2026

PROPOSAL

ABSORBS MEDIARULES

A Saturn game is a video game, plus three things.

Each platform has details only its collectors care about. A Saturn game has a spine card. A Neo Geo game is either AES or MVS. An N64 game might need the Expansion Pak. Building a type per platform would split one shelf into forty. Leaving it all in one type means fields that are empty for 95% of items. A subtype inherits the whole type and adds a few fields of its own. That's all a subtype can do.

00 · ONE LEVEL ABOVE · FIELDS EVERY TYPE INHERITS

Some facts apply to any collectible: who signed it, what's inside it. Type → subtype has a parent too: the item. Its fields come for free on wine, vinyl, pins and games. They stay hidden until the item has a value for them, and each one is added with “+ Add” on the item screen. The first case comes from the import (49): a Turtles cart signed by JDG.

ITEM.YML · INHERITED BY EVERY TYPE

fields:
  - title | acquired | price | place | story

  - key: signed            | Signed       | object
    by:          text      # "JDG", "Château Musar"
    dedication:  text?     # "pour Max"
    date:        date?
    proof:       photo?    # photo of the signature,
                           # certificate, event ticket

  - key: contains          | Bundle of    | list<work>
    # empty = a single thing
    # 2+    = a bundle: Doom + Doom 2, a 6-bottle
    #         case, a vinyl box set, a pin set
    sealed:      bool      # still in the bundle?

WHY AN OBJECT, NOT A BOOL

“Signed” alone doesn't say much. Who signed it is what collectors talk about and what buyers ask. A dedication to a named person lowers resale value, while proof raises it. A plain yes/no would throw both away.

What it drives: a “Signed” badge on the shelf tile, a one-of-a-kind entry in the log, and a filter (“everything signed by JDG”). Signed items are never treated as duplicates.

Bundles are also a list, not an is_bundle flag. “Doom + Doom 2” is one object on the shelf but two works. Series sets and “also exists on” (47) must count both, or the Doom tracker misses one. A flag would say “bundle” without saying of what. The bundle is a derived value: contains.length > 1. It renders with the existing case signature, so no new UI is needed.

The rule for this level: a field goes here only if it means the same thing for every type. Signed passes the test. Condition doesn't, because grading a wine and grading a cart are different scales.

01 · THE RULE

The thesis still holds: the app owns the verbs, the type owns the nouns, and a subtype can only add nouns. Item screen, signatures and slots don't change. A subtype is a short list of extra fields and a few presets.

02 · SAME TYPE, DIFFERENT SUBTYPES

Pick a subtype. Grey fields come from the parent type and are identical everywhere. Coloured ones are what the subtype adds. Storage and care are where platforms differ most: a Game Boy cart and a Saturn disc age in completely different ways.

FIELDS

ADDED BY {{ cur.name }}

{{ a.k }} · {{ a.kind }}

PRESETS · VALUES THE SUBTYPE FILLS IN OR NARROWS

STORAGE

CARE · CLOCKS FROM THE LIBRARY

03 · WHAT IT REPLACES

43 used a mediaRules table so that one field could change the clock, lookup and parts. That was already a subtype, just keyed on media instead of platform. Platform is the better key, because it implies the media in nearly every case and collectors already shelve by platform.

VIDEO-GAME.YML · AFTER

type: video-game
fields: [title, platform, region, edition,
         condition, saveBattery, playStatus, …]

subtypes:
  - key: saturn
    label: Sega Saturn
    presets:
      media: disc
      region: [NTSC-J, NTSC-U, PAL]
      parts: [case, manual, disc, spineCard]
    adds:
      - spineCard   | Spine card     | bool
      - ramCart     | Needs RAM cart | enum [1MB, 4MB]
      - satakore    | Satakore ID    | text

CONSEQUENCES

04 · WHY IT HELPS THE STAGED LAUNCH

You said you'd rather ship a few types that are well tested. Subtypes let that happen at a finer grain.

05 · OPEN QUESTIONS