def format_iteration_coordinate(coord, prefix=None):
    """
    Format the iteration coordinate to a human-readable string.

    Parameters
    ----------
    coord : list
        List containing the iteration coordinate.

    prefix : str or None
        Prefix to prepend to iteration coordinates.

    Returns
    -------
    str :
        iteration coordinate converted to a string
    """
    separator = '|'
    iteration_number_separator = '-'
    iteration_coordinate = []
    for name, local_coord in zip(coord[1::2], coord[2::2]):
        iteration_coordinate.append(name)
        iter_str = map(str, local_coord)
        coord_str = iteration_number_separator.join(iter_str)
        iteration_coordinate.append(coord_str)
    if prefix:
        prefix = '%s_rank%d' % (prefix, coord[0])
    else:
        prefix = 'rank%d' % coord[0]
    return ':'.join([prefix, separator.join(iteration_coordinate)])
