>DB-level metadata I've used it for years - usually auto-populated from the model that builds the relational schema (like you had done). Same for constraints.

>DB-level metadata I've used it for years - usually auto-populated from the model that builds the relational schema (like you had done). Same for constraints. By coincidence, I just convinced my team to start using sp_addextendedproperty. That's the advantage of using a higher-level notation, such as UML or code-first EF, for your ORM. Good idea on the C# type naming conventions.