{ "id": "HostnameOrIPv4AddressOrEmptyString", "maxLength": 255, "module_id": "Common", "pattern": "^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?(?:\\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?)*\\.?$|^$", "title": "Hostname or IPv4 address", "type": "string" }