Using "null=True" on string-based fields can lead to inconsistent and unexpected behavior. In Django, "null=True" allows the field to have a NULL
value in the database. However, the Django convention to represent the absence of data for a string is an empty string. Having two ways to represent
the absence of data can cause problems when querying and filtering on the field. For example, if a CharField with "null=True" has a value of NULL in
the database, querying for an empty string will not return that object.
