1. A default record per entity
2. A field that is derived from another field
3. A SET(…) delete handler with the object as parameter
4. Annotate a condition as BooleanField
5. Date(Time)Fields that store a week or month
6. Dictionary lookups for the database
7. Match multiple strings in a case-insensitive manner
8. querying in the opposite direction
9. Set values to a created/updated object in a class-based view