{ "$schema" : "http://json-schema.org/draft-04/schema#", "type" : "object", "title" : "pin", "rel" : "pin", "description" : "Card PIN code", "parent" : "card", "properties": { "id": { "$ref" : "../base_types/base_types.json#definitions/id" }, "account_id" : { "$ref" : "../base_types/base_types.json#definitions/account_id" }, "pin" : { "description" : "Personal identification number of the card", "type" : "string", "pattern" : "^[0-9]{4}$" } } }