def get_anonymous_dimension_indices(c):
    """
    Returns a list of indices of anonymous dimensions of a given iris cube.

    Parameters
    ----------
    c : iris cube
        Cube whose anonymous dimensions are to be found.

    Returns
    -------
    l : list
        List of anonymous dimension indices.

    """
    all_dims = set(range(c.ndim))
    covered_dims = set(c.coord_dims(coord)[0] for coord in c.dim_coords)
    anonymous_dims = all_dims - covered_dims
    return list(anonymous_dims)