def parsedefaultmarker(text):
    """given a text 'abc (DEFAULT: def.ghi)',
    returns (b'abc', (b'def', b'ghi')). Otherwise return None"""
    if text[-1:] == b')':
        marker = b' (DEFAULT: '
        pos = text.find(marker)
        if pos >= 0:
            item = text[pos + len(marker) : -1]
            return text[:pos], item.split(b'.', 2)