{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://rig.works/schemas/rig.book.identifier.schema.json",
  "title": "rig.book.identifier",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "isbn13": {
      "type": "string",
      "pattern": "^97[89][0-9]{10}$",
      "description": "ISO 2108 ISBN-13 digits only (ONIX ProductIDType 15)."
    },
    "isbn10": {
      "type": "string",
      "pattern": "^[0-9]{9}[0-9X]$",
      "description": "ISO 2108 ISBN-10 (ONIX ProductIDType 02). Legacy."
    },
    "doi": {
      "$ref": "./_defs.schema.json#/$defs/string"
    },
    "issn": {
      "type": "string",
      "pattern": "^[0-9]{4}-[0-9]{3}[0-9X]$",
      "description": "ISSN (ISO 3297)."
    }
  },
  "description": "Product identifiers. Prefer isbn13 (ISO 2108). Do not invent isbn10 from isbn13.",
  "minProperties": 1
}