def fix_week_14(df):
    """
    For annotations from week 14:
    - Replace MBW values with `False`
    - Replace MBW-lvl values with NaN
    We remove this domain from week 14 since the guidelines for it were changed after this week.

    Parameters
    ----------
    df: DataFrame
        parsed token-level annotations df (created by `parse_annotations.py`)

    Returns
    -------
    DataFrame
        df without MBW and MBW_lvl labels for week 14
    """

    df['MBW'] = df.MBW.mask(df.batch == 'week_14', other=False)
    df['MBW_lvl'] = df.MBW_lvl.mask(df.batch == 'week_14')

    return df