# TYP-1 — Display and body/UI text use the typefaces and weights the product's DESIGN.md declares (else the codebase's font tokens, else Tailwind's default font stacks); no other typefaces

L1 · deterministic · Typography

**Fails when:** any other typeface in product UI, except a product's registered brand-wordmark typeface confined to its wordmark/logo lockup (declared in the product's DESIGN.md)

## Requirement

Product UI is set in the product's declared **display** typeface and its declared
**body/UI** typeface, at the declared weights. No other typeface — with one registered
exception: a product's **brand wordmark** may use its own settled wordmark typeface,
**confined to the wordmark/logo lockup** (the product name / masthead mark), never for
running display, headings, or body text.

This is the typographic analogue of COL-1's per-product primary colour: a wordmark is
a brand asset (cf. IDN-1 for logo *images*), and a settled wordmark typeface is
registered in the product's `DESIGN.md` rather than re-flagged as a violation on every surface that renders
the mark.

## Where the values come from

The product's `DESIGN.md` declares the typefaces and weights. Where it declares none,
the codebase's own font tokens (for example, `--font-display` and `--font-body`) decide.
Where neither does, Tailwind's default font stacks apply. This site's `DESIGN.md`, for
example, declares Plus Jakarta Sans (600) for display and Inter (400/500/600) for body
and UI text.

## Per-product registered brand wordmark

Each product registers its settled wordmark typeface, if it has one, in its
`DESIGN.md`: the typeface, the token that carries it (for example, `--font-logo`), and
the lockup it is confined to. A product with no separate wordmark face sets its mark in
its display typeface.

A typeface not registered this way, or the registered wordmark face used **outside** its
lockup (as heading or body type), is a TYP-1 finding.

## Rationale

In a product pilot, a deliberate wordmark lockup set in its own typeface was flagged by
TYP-1 as written ("no other typefaces") as a hard L1 violation, requiring a hand-written
waiver on every surface that renders the mark. COL-1 already
registers each product's primary *colour*; IDN-1 protects logo
*images*; TYP-1 had no analogue for a wordmark *typeface*. Registering the settled
wordmark face, scoped to the lockup, stops the recurring waiver while keeping the
"no other typeface in running UI" rule intact.

Note the failure mode this does **not** excuse: a dead font `@import` (a typeface
loaded but used by nothing — for example, a shipped-but-unused Geist import) is still a
TYP-1 finding. The exception covers a *used* wordmark face, not loaded dead bytes.

## How to verify

**Script (literal families only):** `checks/type-scan` reads each resolvable literal
family, in a CSS `font-family` or a Tailwind `font-[…]` value, and flags a primary
family that is not on its fixed list. The list holds Plus Jakarta Sans, Inter, the
font-token names (`font-display`, `font-body`, `font-sans`, `--font-display`,
`--font-body`), and common sans fallbacks such as `system-ui`, Helvetica, and Arial.
The script also flags the `font-serif` and `font-mono` utilities. The list is fixed in
the script and does not come from `DESIGN.md`. A face your `DESIGN.md` declares can
still be flagged by its literal name, so check such a finding against `DESIGN.md`
before you report it. A face on the list passes the script even when your product does
not declare it.

**Evaluator (no script coverage):** check each of these by hand.

- **Literal families, flagged or accepted.** Check every literal primary family against
  the product's typefaces: the ones `DESIGN.md` declares, else the codebase's font
  tokens, else Tailwind's default stacks. This includes every family the script
  accepts. A literal `font-family: "Inter"` in a product whose `DESIGN.md` declares a
  different face is a finding, although the script passes it.
- **Token-to-family mappings.** The script passes any `var(--…)` family without
  resolving it. Confirm each font token resolves to a face `DESIGN.md` declares, or,
  where it declares none, to the codebase's font tokens or Tailwind's default stacks.
- **Weights.** The script does not check weights. Confirm each face is used only at
  the weights `DESIGN.md` declares.
- **Wordmark registration and scope.** Confirm a wordmark face is registered in
  `DESIGN.md`, and that it appears only in the wordmark/logo lockup, not in headings or
  body. Wordmark-in-lockup passes; wordmark-as-heading is a finding.
- **Unused imports.** The script does not read imports. Confirm every face the product
  loads (`@import`, `@font-face`, or a font package) is used.