Should the PVP be changed with regards to instances?

[Henning Thielemann]

On Tue, 20 Dec 2011, Ganesh Sittampalam wrote:

> I'd argue against this: users who write orphan instances typically have
> no choice, even if they know it's problematic. Contrast this to the fact
> that we do allow new exports, because a cautious user of the package can
> avoid problems by explicitly listing what they import.

The clean solution for orphan instances are separate modules that are 
approved by the maintainers of the concerned class and type. If the 
instance can be easily added to the package of the class or the package of 
the type, then it should be added there.