def message_prefix(file_format, run_type):
    """Text describing saved case file format and run results type."""
    format_str = ' format' if file_format == 'mat' else '  format'
    if run_type == ['PF run']:
        run_str = run_type + ': '
    else:
        run_str = run_type + ':'
    return 'Savecase: ' + file_format + format_str + ' - ' + run_str