/** The key of the configuration. e.g. userCode */
    String USER_CODE_REQUEST_PARAMETER = "user.code.request.parameter";

    /** The key of the configuration. e.g. 20 */
    String USER_CODE_MIN_LENGTH = "user.code.min.length";

    /** The key of the configuration. e.g. 100 */
    String USER_CODE_MAX_LENGTH = "user.code.max.length";

    /** The key of the configuration. e.g. [a-zA-Z0-9_]+ */