Another possibility is do use Integers, but define a Constant class Value.

```python
class Item(models.Model):
    AGENDA_ITEM = 1
    ORGANIZATIONAL_ITEM = 2
    ITEM_TYPE = (
        (AGENDA_ITEM , _(...),
        ...
    type = models.IntegerField(...)

Item.objects.filter(type=Item.AGENDA_ITEM)
```
Like in this example, but with an IntegerField. https://docs.djangoproject.com/en/dev/ref/models/fields/#choices
But it is just an suggestion. You can do it your way.