from pandas import DataFrame, Series

def signals(data: DataFrame) -> Series:
    """
    Calculate the Internal Bar Strength (IBS) signal.
    Returns a Series with 'L' for long signals and 'N' otherwise.
    """
    ibs_series = (data['Close'] - data['Low']) / (data['High'] - data['Low'])
    return ibs_series.apply(lambda ibs: 'L' if ibs < 0.2 else 'N')