Idiolect, dialect, language

The project borrows three linguistic terms to distinguish individual practice, community policy, and shared infrastructure. The analogy is organizational; it does not claim that schema systems have every property of natural languages.

Three levels

An idiolect is one publisher's practice: the record types it emits, the lenses it uses, and the conventions it follows. There is no dev.idiolect.idiolect record. An idiolect is inferred from records; a dialect's idiolects field lists the schema references that constitute its idiolect set.

A dialect is an explicit community bundle. A dev.idiolect.dialect record names its owning community and may carry schema references in idiolects, along with preferredLenses, deprecations, and version links. The dialect is policy expressed as data; consuming it remains a local choice.

The language level (LL) is the shared ATProto substrate plus the schema and lens records published on it. The LL has no single runtime record and no requirement that all participants use one schema. Local catalogs, indexers, and orchestrators construct views over this level.

Plural canonicity

The model permits more than one community to call a different bundle canonical. We call this plural canonicity (PC). A consumer resolves PC locally by choosing which community records, recommendations, vocabularies, and observers it trusts. The orchestrator's catalog supports that selection; it does not make the selection universal.

PC has two consequences. First, a new schema can be published without a network-wide approval step. Second, a lens can connect established schemas without forcing either publisher to rename its collection. But the same freedom allows incompatible or malicious records, so policy cannot be derived from federation alone.

Failure modes

Three failure modes recur at different levels:

1. Unlinked duplication. Two NSIDs describe similar data, but no lens or recommendation relates them. Consumers must either treat them separately or author the missing relationship.
2. Vocabulary collision. Two communities reuse a slug with different intended meanings. A *Vocab reference can disambiguate the vocabulary, but an omitted reference may leave policy to a canonical default outside the wire record.
3. Dialect drift. A community updates a dialect's preferred lenses or deprecations. An AT-URI may then resolve to a new record CID while consumers holding an older strong reference continue to see the pinned revision.

A potential worry about PC is that it merely renames fragmentation. That worry is justified when publishers supply no lenses, evidence, or policy records. The model does not prevent that outcome. It makes the missing relationships visible and gives later publishers a common place to add them.

The actual guarantees

An NSID identifies an intended Lexicon shape, but repositories remain untrusted input; invalid records may appear on an event stream. A generated decoder can reject a record it cannot deserialize, though not every semantic constraint is enforced by deserialization alone. Likewise, a lens carries law claims, but those claims require checking on concrete instances or stronger external evidence.

Thus, the three levels distribute responsibility rather than truth. Publishers choose an idiolect, communities state a dialect, and consumers decide how to interpret the language-level record population. The dev.idiolect.* family supplies the records used in that exchange.