def format_suffix(altradio=None, radioversion=None, core=False):
    """
    Formulate suffix for hybrid autoloaders.

    :param altradio: If a hybrid autoloader is being made.
    :type altradio: bool

    :param radioversion: The hybrid radio version, if applicable.
    :type radioversion: str

    :param core: If we're using a core OS image. Default is false.
    :type core: bool
    """
    suffix = "_R{0}".format(radioversion) if altradio and radioversion else ""
    if core:
        suffix += "_CORE"
    return suffix