Idiolect, dialect, language

The project name comes from a deliberate analogy with the linguistic terms.

• An idiolect is one party's choice of schemas, lenses, and conventions. It is what a single PDS (or a single application developer) actually publishes.
• A dialect is the bundle of idiolects a community treats as canonical. It carries a list of preferred NSIDs, preferred lenses, endorsed vocabularies, and deprecations.
• A language is the federated substrate over which idiolects and dialects meet. There is no central registry, no single authority, and no global schema; the substrate is ATProto plus the shipped lexicons.

The three layers correspond to three things in the runtime:

Why this frame

A large protocol benefits from a model where parties can disagree gracefully. Two communities can run incompatible schemas and the substrate accommodates them; a third community can publish a lens between the two and the network can route translations. The frame does not promise a single canonical schema; it ships the machinery for reasoning about plural canonicities.

The properties this gets you:

• No global arbiter. There is no place to file a grievance and no place to extract rent. A community can fork a dialect, ship its own, and let consumers pick.
• Cheap experimentation. Adding an idiolect is a record edit. A community can try a new schema, see who adopts, and either roll it into a dialect or abandon it.
• Auditable convergence. When two communities adopt the same lens, the encounter / observation / recommendation records carry enough structure to make the convergence visible without a central monitor.

Failure modes the frame admits

The frame does not promise that the network converges, that disagreements always resolve, or that bad actors cannot publish records. It admits:

• Silent fragmentation. Two communities ship near-identical schemas under different NSIDs. Consumers see two records where there should be one. The signal is the lens-recommendation density between the two; if no community publishes a lens between them, the fragmentation is permanent.
• Adversarial publishing. A bad actor publishes a vocab that shadows a canonical slug with a different meaning. The containment is at the consumer's policy: prefer vocabs from recognised communities, treat unknown vocabs as unknown.
• Dialect drift. A community changes its dialect record without coordinating with downstream consumers. Old records keep validating; new lens choices route differently. The signal is the deprecation list and the lexicon-evolution gate.

The runtime ships primitives for each of these (recommendation, deliberation, lens classification) but no policy. Policy lives in the consumer.

What is not promised

The frame does not promise a unified ontology, a global identifier scheme, or a single authoritative type for any record kind. It does promise that two parties using the same NSID see records under that NSID with the same wire shape, that lenses between schemas obey their stated laws, and that the lexicon itself does not change shape without an auditable migration.

The chapters that follow cover what each of those promises means in practice.