def read_metadata_tf(line, search_text, current_value):
    """
    function to read simple DynAdjust header items and return True/False
    :param line: DynAdjust header line
    :param search_text: header field desired.
    :param current_value: stored value. Updated when search_text is successfully found.
    :return: either current value or True/False corresponding to search_text
    """
    if line[:35] == search_text.ljust(35, ' '):
        if line[35:].strip() == 'Yes':
            return True
        else:
            return False
    else:
        return current_value