• Date: 2026-06-18
• Status: Accepted (codifies existing convention; now load-bearing)
• Builds on: the prose rule in Rules.md §"Naming chord — Arno + Renaissance"

Context

ARNO's name is the river Arno in Tuscany, on whose banks the Renaissance was born. Two product surfaces already lean into this — Arno Foundation (after Vasari's La Pratica della Pittura, the practitioner's canon) and Arno Sorgente (after Sorgente del Falterona, the physical wellhead of the Arno river — see ADR 0049). The chord exists; it just needs to be a load-bearing rule rather than a stylistic preference.

The Studio tooling layer adopted the chord in practice during the 2026-06 docs scaffolding wave: punta (Italian tip / point), dito (finger), passo (step / pace), tela (canvas / cloth). Three more Studio tools (canvas, adaptive, nav-bar, sidebar) carry working English names with Italian candidates documented in their _index.md files pending a final rename pass.

Without an explicit rule, a future contributor reading the codebase sees:

• Italian-named tools (punta, dito, passo, tela) — looks intentional
• English-named tools (nav-bar, sidebar, canvas, adaptive) — looks like an oversight
• Working-name flags ("candidate: tela / quadro") in _index.md files — looks like indecision

The mix reads as drift. Either Italian is the rule (English is the temporary state pending rename) or there is no rule and the Italian names are personal style. The former is true; this ADR makes it written.

Decision

Every Studio tool name and every publicly-visible product surface name follows the Italian / Renaissance chord. Rule:

1. Italian noun preferred — short (≤ 8 chars when possible), concrete, traceable to a Renaissance craft / artistic vocabulary.
2. Lexically unique in SEO — Google the candidate; the first page should not be dominated by an unrelated existing brand or generic noun.
3. Metaphor transparent without footnote — a designer reading the name should grasp the connection in one sentence ("punta = tip of an engraving tool, applied to the precise point where the designer touches a value").
4. No generic English replacements — core, source, hub, panel, tools, editor are forbidden as tool names.
5. Pair-wise coherence — tool names that work together are stronger when their metaphors overlap (punta / dito / passo — three Italian artisan gestures; tela / quadro — two painter's-surface terms).

Canonical product names (locked)

• ARNO — the product. Named after the river in Tuscany.
• Arno Foundation — packages/foundation/ design-system source-of-truth. From Vasari's La Pratica della Pittura.
• Arno Sorgente — self-hosting / dogfooding project. From Sorgente del Falterona, the physical source of the Arno. See ADR 0049.

Studio tool names (live)

Studio tool names (working — pending final rename)

The working names are explicitly flagged in each tool's _index.md so that a future rename pass picks them up.

Layer-type taxonomy

The shared layerTypeOf dispatch (see ADR 0061) uses the English terms box / text / component because they are domain primitives, not product surfaces. Italian terms for layer types are reserved (scatola, testo, componente) but not adopted — the English forms are short, unambiguous, and self-explanatory to a TypeScript reader.

Enforcement

PR review. A new Studio tool name that does not pass the four-point checklist above is rejected at review with one of the failing criteria cited.

A CI check is intentionally NOT proposed for naming — naming is a judgment call that benefits from human review, not regex.

Consequences

Positive

• Coherent identity surface. Designers and contributors read the tool list as a clear chord: this is a deliberate, considered product. Industry-recognised pattern (think Stripe's geographic names for packages, Linear's mythology references).
• SEO benefit. Lexically unique product names are searchable and trademarkable. punta + arno returns this product first; sidebar + arno is drowned in generic results.
• Memorability. Designers remember punta / dito / passo because they form a story (tip, finger, step — the gestures of touching). Generic names do not story.
• Cross-tool metaphor reuse. tela (canvas) sits behind quadro (frame) sits in cornice (frame chrome) — three painter's-workshop terms in one visual layout. The metaphor pays the cognitive cost back tenfold.

Negative

• Onboarding tax. A contributor from outside the Italian-language sphere needs ~30 seconds to learn each name. We accept this; the chord is worth it.
• Translation burden. Italian glosses appear in every tool's glossary.md and README.md to keep the metaphor surfaced. ~3 lines per tool.
• Pressure to find an Italian word for everything. A few legitimately neutral names (nav-bar, sidebar) might force a stretched Italian metaphor. Mitigation: working names with explicit candidates are acceptable indefinitely until a strong Italian candidate emerges.

Risk: cargo-culting

The biggest failure mode is naming a tool with an Italian word that does not carry the chord (e.g. naming a button "bottone" because it is the Italian for button — that is direct translation, not metaphor). Mitigation: every name must clear the "metaphor transparent without footnote" rule. "Bottone" fails this.

Alternatives considered

• English-only naming. Rejected — drops the chord that Arno + Foundation + Sorgente already established.
• Polyglot mythology (mix Italian, Latin, Greek). Rejected — dilutes the chord. Italian alone is coherent.
• Numeric / alphabetic identifiers. Rejected — fails on memorability and identity.
• Auto-generate names from a Renaissance vocabulary corpus. Rejected — the metaphor-transparency rule requires human judgment, not random selection.

References

• ADR 0049 (Arno Sorgente naming rationale — sets the Tuscan-river-source chord).
• Rules.md §"Naming chord — Arno + Renaissance" (the prose rule that points to this ADR).
• Industry: Stripe's geographic package names (stripe-tipsi, stripe-react), Linear's mythology references (Wormhole, Helios), Atlassian Jira/Confluence (sword + dove imagery). Naming chords are a battle-tested DS pattern.