Lexicon is the schema language for records, API calls and streams; each schema has an NSID whose reversed domain says who owns it; schemas are published as records; any app can read any other app's records.

Shared, owned schemas are how independent apps interoperate on one network.

What is a post? A like? A recipe? A Lexicon says. Lexicon is the dictionary: the schema language for records, API calls, and streams.

Every schema has a namespaced ID. Reverse the domain, add a name. Whoever controls the domain controls the schema.

A schema defines a record type, a query, a procedure, a subscription, or a bundle of permissions. Typed fields, references, blobs, unions.

Schemas are published as records, in a repository. A DNS record on the domain says which DID holds them.

So any app can read any other app's records, and know what they mean. The schema is public, named, and owned.

Check yourself. How does a developer prove they own a schema name?