{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://ucp.dev/2026-08-25/schemas/common/types/reverse_domain_name.json",
  "title": "Reverse Domain Name",
  "description": "Reverse-domain identifier used for collision-safe namespacing of capabilities, services, handlers, eligibility claims, and extension-contributed keys. Must contain at least two dot-separated segments (e.g., 'dev.ucp.shopping.checkout', 'com.example.loyalty_gold'). Segments after the first are domain- or identifier-derived: they may contain interior hyphens, may start with a digit, and may contain underscores (e.g., 'com.example-shop.checkout', 'com.2example.cart', 'dev.ucp.common.identity_linking'), but must not start or end with a hyphen. The first segment (the reversed top-level domain) is letters and digits, and may contain interior hyphens to support internationalized (punycode) top-level domains such as 'xn--p1ai'.",
  "type": "string",
  "pattern": "^[a-z](?:[a-z0-9-]*[a-z0-9])?(?:\\.[a-z0-9](?:[a-z0-9_-]*[a-z0-9_])?)+$",
  "examples": [
    "dev.ucp.shopping.checkout",
    "dev.ucp.common.identity_linking",
    "com.example.loyalty_gold",
    "com.example-shop.checkout",
    "com.2example.cart",
    "uk.co.example-shop.checkout",
    "xn--p1ai.example.checkout"
  ]
}