How to use Django 3.2 CreateCollation and db_collation to implement a case-insensitive Charfield with Postgres > 12

case_insensitive_charfield.py

# According to Django documentation, it’s preferable to use non-deterministic collations
# instead of the citext extension for Postgres > 12.

# Example migation to create the case insensitive collation

class Migration(migrations.Migration):

    operations = [
        CreateCollation(
            'case_insensitive',
            provider='icu',
            locale='und-u-ks-level2',
            deterministic=False
        )
    ]


# Example model using the new db_collation parameter introduced with Django 3.2

class Tag(models.Model):
    name = models.CharField(max_length=50, db_collation='case_insensitive')

    class Meta:
        ordering = ['name']

    def __str__(self):
        return self.name