I have made a form that contains a field like:

```
sex = forms.ChoiceField(choices= SEX)

```

Where:

```
SEX = (
    ('F','Female'),
    ('M','Male'),
    ('U','Unsure'),
    )

```

Now I'm wondering how best the sex field should be defined the model? I know that it can be done like:

```
class UserProfile(models.Model):
    user = models.ForeignKey('User')
    sex = models.CharField(max_length=10)

```

But isn't there a better option than CharField?