ManyRelatedManager.add() acting funny?

[Jeff Blaine]

What happened here?  Do I not understand .add()?  I would have expected to see

[(u'rcf_clients',)] not [(u'rcf_clients', u'')]

>>> print d.tags.values_list()
[]
>>> d.tags.add('rcf_clients')
>>> d.save()
>>> print d.tags.values_list()
[(u'rcf_clients', u'')]
>>>

[Jeff Blaine]

Nevermind.  I get it.  'tags' has another field, description, which is what the extra u'' is for.